Revised list of TBCs

author: kinitrupti 2017-05-12 18:40:35 +0530
committer: kinitrupti 2017-05-12 18:40:35 +0530
commit: d36fc3b8f88cc3108ffff6151e376b619b9abb01 (patch)
tree: 9806b0d68a708d2cfc4efc8ae3751423c56b7721 /Switchgear_Protection_And_Power_Systems_by_S._S._Rao
parent: 1b1bb67e9ea912be5c8591523c8b328766e3680f (diff)
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diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_17_Electrical_substations_Equipment_and_Bus_bar_Layouts.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_17_Electrical_substations_Equipment_and_Bus_bar_Layouts.ipynb
deleted file mode 100755
index 076a3e15..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_17_Electrical_substations_Equipment_and_Bus_bar_Layouts.ipynb
+++ /dev/null
@@ -1,75 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 17: Electrical substations Equipment and Bus bar Layouts"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 17_1 pgno:329"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 2,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the force on busbar per meter length = kgfper meter 346.461328125\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "Isc= 25e3;\n",
-    "i=2.55*Isc;\n",
-    "L=1;\n",
-    "r=0.24;\n",
-    "#solution\n",
-    "F=2.046*(i**2)*10**-5/r;\n",
-    "print\"the force on busbar per meter length = kgfper meter\",F/1e3\n",
-    "\n"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_17_Electrical_substations_Equipment_and_Bus_bar_Layouts_1.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_17_Electrical_substations_Equipment_and_Bus_bar_Layouts_1.ipynb
deleted file mode 100755
index 7dd70c75..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_17_Electrical_substations_Equipment_and_Bus_bar_Layouts_1.ipynb
+++ /dev/null
@@ -1,66 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 17: Electrical substations Equipment and Bus bar Layouts"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 17_1 pgno:329"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 2,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the force on busbar per meter length = kgfper meter 346.461328125\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "Isc= 25e3;\n",
-    "i=2.55*Isc;\n",
-    "L=1;\n",
-    "r=0.24;\n",
-    "#solution\n",
-    "F=2.046*(i**2)*10**-5/r;\n",
-    "print\"the force on busbar per meter length = kgfper meter\",F/1e3\n",
-    "\n"
-   ]
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_18-b_Nutral_Grounding.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_18-b_Nutral_Grounding.ipynb
deleted file mode 100755
index 60da2578..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_18-b_Nutral_Grounding.ipynb
+++ /dev/null
@@ -1,198 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 18-b Nutral Grounding"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 18_1 pgno:369"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 6,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the value of z= ohm 0.2\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "P=2000e3;\n",
-    "V=400;\n",
-    "r=.4;\n",
-    "#solution\n",
-    "z=V**2/(r*P);\n",
-    "print\"the value of z= ohm\",z\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 18_2 pgno:369"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 7,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "inductance = Henries 22.54\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "w=314;\n",
-    "c=.015e-6;\n",
-    "#solution\n",
-    "l=1/(3*w**2*c);#the difference in result is due to erroneous calculation in textbook.\n",
-    "l=round(l*10)/100;\n",
-    "print\"inductance = Henries\",l\n",
-    "print\"the difference in result is due to erroneous calculation in textbook.\"\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 18_3 pgno:369"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 8,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the inductance for 100 percent line capacitance= henries  2.25\n",
-      "for 90percent line capacitance,the inductance= henries 2.5\n",
-      "for 95percent line capacitane inductance= henries 2.37\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import pi\n",
-    "#given \n",
-    "c1=1.5e-6;\n",
-    "w=2*pi*50;\n",
-    "L1=1/(3*c1*(w**2));\n",
-    "c2=.9*c1;\n",
-    "L2=1/(3*c2*(w**2));\n",
-    "c3=.95*c1;\n",
-    "L3=1/(3*c3*(w**2));\n",
-    "L1=round(L1*100)/100;\n",
-    "L2=round(L2*10)/10;\n",
-    "L3=round(L3*100)/100;\n",
-    "print\"the inductance for 100 percent line capacitance= henries \",L1\n",
-    "print\"for 90percent line capacitance,the inductance= henries\",L2\n",
-    "print\"for 95percent line capacitane inductance= henries\",L3\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 18_4 pgno:369"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 9,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the value of L=H and rating =kVA 6.75 171.28250436\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "from math import pi,sqrt\n",
-    "c=.01e-6*50;\n",
-    "w=2*pi*50;\n",
-    "L=1/(3*c*(w**2));\n",
-    "#solution\n",
-    "L=round(L*100)/100;\n",
-    "V=33e3/sqrt(3);\n",
-    "I=V/(w*L);\n",
-    "I=round(I*1000)/1000;\n",
-    "I=round(I*100)/100;\n",
-    "R=V*I/1e3; #the difference in result is due to erroneous calculation in textbook.\n",
-    "print\"the value of L=H and rating =kVA\",L,R\n",
-    "print\"the difference in result is due to erroneous calculation in textbook.\"\n"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_18-b_Nutral_Grounding_1.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_18-b_Nutral_Grounding_1.ipynb
deleted file mode 100755
index 6d358d9e..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_18-b_Nutral_Grounding_1.ipynb
+++ /dev/null
@@ -1,180 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 18-b Neutral Grounding"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 18_1 pgno:369"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 6,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the value of z= ohm 0.2\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "P=2000e3;\n",
-    "V=400;\n",
-    "r=.4;\n",
-    "#solution\n",
-    "z=V**2/(r*P);\n",
-    "print\"the value of z= ohm\",z\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 18_2 pgno:369"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 7,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "inductance = Henries 22.54\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "w=314;\n",
-    "c=.015e-6;\n",
-    "#solution\n",
-    "l=1/(3*w**2*c);#the difference in result is due to erroneous calculation in textbook.\n",
-    "l=round(l*10)/100;\n",
-    "print\"inductance = Henries\",l\n",
-    "print\"the difference in result is due to erroneous calculation in textbook.\"\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 18_3 pgno:369"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 8,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the inductance for 100 percent line capacitance= henries  2.25\n",
-      "for 90percent line capacitance,the inductance= henries 2.5\n",
-      "for 95percent line capacitane inductance= henries 2.37\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import pi\n",
-    "#given \n",
-    "c1=1.5e-6;\n",
-    "w=2*pi*50;\n",
-    "L1=1/(3*c1*(w**2));\n",
-    "c2=.9*c1;\n",
-    "L2=1/(3*c2*(w**2));\n",
-    "c3=.95*c1;\n",
-    "L3=1/(3*c3*(w**2));\n",
-    "L1=round(L1*100)/100;\n",
-    "L2=round(L2*10)/10;\n",
-    "L3=round(L3*100)/100;\n",
-    "print\"the inductance for 100 percent line capacitance= henries \",L1\n",
-    "print\"for 90percent line capacitance,the inductance= henries\",L2\n",
-    "print\"for 95percent line capacitane inductance= henries\",L3\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 18_4 pgno:369"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 9,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the value of L=H and rating =kVA 6.75 171.28250436\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "from math import pi,sqrt\n",
-    "c=.01e-6*50;\n",
-    "w=2*pi*50;\n",
-    "L=1/(3*c*(w**2));\n",
-    "#solution\n",
-    "L=round(L*100)/100;\n",
-    "V=33e3/sqrt(3);\n",
-    "I=V/(w*L);\n",
-    "I=round(I*1000)/1000;\n",
-    "I=round(I*100)/100;\n",
-    "R=V*I/1e3; #the difference in result is due to erroneous calculation in textbook.\n",
-    "print\"the value of L=H and rating =kVA\",L,R\n",
-    "print\"the difference in result is due to erroneous calculation in textbook.\"\n"
-   ]
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_19_Introduction_to_Fault_Calculations.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_19_Introduction_to_Fault_Calculations.ipynb
deleted file mode 100755
index 0948ab5c..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_19_Introduction_to_Fault_Calculations.ipynb
+++ /dev/null
@@ -1,346 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 19 Introduction to Fault Calculations"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 19_1 pgno:392"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 10,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the base impedence=ohm\n",
-      "20.0\n",
-      "the base values for 20A=p.u. 2.0\n",
-      " the base values for 2A=p.u. 0.02\n",
-      "the base values for 50V=p.u. 0.25\n",
-      "the base values for 2ohm=p.u 0.1\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "i=10.;\n",
-    "v=200.;\n",
-    "#solution\n",
-    "z=v/i;\n",
-    "I1=20/i;\n",
-    "I2=.2/i;\n",
-    "v1=50/v;\n",
-    "r=2/z;\n",
-    "print\"the base impedence=ohm\\n\",z\n",
-    "print\"the base values for 20A=p.u.\",I1\n",
-    "print\" the base values for 2A=p.u.\",I2 \n",
-    "print\"the base values for 50V=p.u.\",v1  \n",
-    "print\"the base values for 2ohm=p.u\",r\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 19_2 pgno:393"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 11,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the per unit resistance=p.u 0.0165\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "z=2;\n",
-    "v=11e3;\n",
-    "r=1000e3;\n",
-    "#solution\n",
-    "zb=v**2/r;\n",
-    "y=z/zb;\n",
-    "y=round(y*10000)/10000;\n",
-    "print\"the per unit resistance=p.u\",y\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 19_3 pgno:393"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 12,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the new per unit reactance=p.u 0.0003\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "v=11e3;\n",
-    "r=15000e3;\n",
-    "zp=.15;\n",
-    "vnew=110e3;\n",
-    "rnew=30000e3;\n",
-    "#solution\n",
-    "zb=v**2/r;\n",
-    "Z=zp*zb;\n",
-    "zbnew=vnew**2/rnew;\n",
-    "Zp=Z/zbnew;\n",
-    "print\"the new per unit reactance=p.u\",Zp/10\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 19_4 pgno:394"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 13,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the per unit values =p.u. ; p.u.; p.u.  276.0 276.0 276.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "v1=11e3;\n",
-    "v2=22e3;\n",
-    "v3=3.3e3;\n",
-    "r=10000e3;\n",
-    "#solution\n",
-    "zb1=v1**2/r;\n",
-    "zb2=v2**2/r;\n",
-    "zb3=v3**2/r;\n",
-    "zp1=300/zb3;\n",
-    "zp2=300*(zb2/zb3)/zb2;\n",
-    "zp3=300*(zb1/zb3)/zb1;\n",
-    "zp1=round(zp1*10)/10;\n",
-    "zp1=round(zp1);\n",
-    "zp2=round(zp2*10)/10;\n",
-    "zp2=round(zp2);\n",
-    "zp3=round(zp3*10)/10;\n",
-    "zp3=round(zp3);\n",
-    "print\"the per unit values =p.u. ; p.u.; p.u. \",zp1,zp2,zp3\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 19_5 pgno:397"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 14,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the fault current is =+(j)A 0.0 -11.5\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "\n",
-    "z=complex(0,0.2*0.155/(0.2+0.155));\n",
-    "v=1;\n",
-    "i=v/z;\n",
-    "\n",
-    "print\"the fault current is =+(j)A\",i.real,round(i.imag,1)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 19_6 pgno:397"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 15,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the base impedence of transmission line circuti=ohm\n",
-      "per unit reactance of transmission line=p.u.\n",
-      "  403.333333333 0.198347107438\n",
-      "per unit reactance of transformer to new base=+(j)p.u.\n",
-      "Per unit reactance of motor to new base=+(j)p.u. 0.0 0.0857142857143 0.0 0.6\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "r=30000e3;\n",
-    "v1=11e3;\n",
-    "v2=110e3;\n",
-    "zb1=v1**2/r;\n",
-    "zb2=v2**2/r;\n",
-    "zp1=80./zb2;\n",
-    "zp2=complex(0,.1*30000./35000.);\n",
-    "zp3=complex(0,.2*30000./10000.);\n",
-    "\n",
-    "print\"the base impedence of transmission line circuti=ohm\\nper unit reactance of transmission line=p.u.\\n \",zb2,zp1\n",
-    "print\"per unit reactance of transformer to new base=+(j)p.u.\\nPer unit reactance of motor to new base=+(j)p.u.\",zp2.real,zp2.imag,zp3.real,zp3.imag\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 19_7 pgno:398"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 16,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the per unit impedencce of circuit \n",
-      "Zp=jp.u ;\n",
-      " Zs=jp.u;\n",
-      " Zt=jp.u 0.035 0.03 0.05\n"
-     ]
-    }
-   ],
-   "source": [
-    "r1=10e6;\n",
-    "r2=7.5e6;\n",
-    "r3=5e6;\n",
-    "v1=66e3;\n",
-    "v2=11e3;\n",
-    "v3=3.3e3;\n",
-    "zst=complex(0,.06*r1/r2);\n",
-    "zps=complex(0,.07);\n",
-    "zpt=complex(0,.09)\n",
-    "Zp=(zst+zps-zst)/2;\n",
-    "Zs=(zps+zst-zpt)/2;\n",
-    "Zt=(zpt+zst-zps)/2;\n",
-    "print\"the per unit impedencce of circuit \\nZp=jp.u ;\\n Zs=jp.u;\\n Zt=jp.u\",Zp.imag,Zs.imag,Zt.imag\n",
-    "      "
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 19_9 pgno:399"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 17,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "new fault =MVA 4800\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "old=5000;\n",
-    "bank=200;\n",
-    "#solution\n",
-    "new=old-bank;\n",
-    "print\"new fault =MVA\",new\n"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_19_Introduction_to_Fault_Calculations_1.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_19_Introduction_to_Fault_Calculations_1.ipynb
deleted file mode 100755
index a797d4ab..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_19_Introduction_to_Fault_Calculations_1.ipynb
+++ /dev/null
@@ -1,337 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 19 Introduction to Fault Calculations"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 19_1 pgno:392"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 10,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the base impedence=ohm\n",
-      "20.0\n",
-      "the base values for 20A=p.u. 2.0\n",
-      " the base values for 2A=p.u. 0.02\n",
-      "the base values for 50V=p.u. 0.25\n",
-      "the base values for 2ohm=p.u 0.1\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "i=10.;\n",
-    "v=200.;\n",
-    "#solution\n",
-    "z=v/i;\n",
-    "I1=20/i;\n",
-    "I2=.2/i;\n",
-    "v1=50/v;\n",
-    "r=2/z;\n",
-    "print\"the base impedence=ohm\\n\",z\n",
-    "print\"the base values for 20A=p.u.\",I1\n",
-    "print\" the base values for 2A=p.u.\",I2 \n",
-    "print\"the base values for 50V=p.u.\",v1  \n",
-    "print\"the base values for 2ohm=p.u\",r\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 19_2 pgno:393"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 11,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the per unit resistance=p.u 0.0165\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "z=2;\n",
-    "v=11e3;\n",
-    "r=1000e3;\n",
-    "#solution\n",
-    "zb=v**2/r;\n",
-    "y=z/zb;\n",
-    "y=round(y*10000)/10000;\n",
-    "print\"the per unit resistance=p.u\",y\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 19_3 pgno:393"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 12,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the new per unit reactance=p.u 0.0003\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "v=11e3;\n",
-    "r=15000e3;\n",
-    "zp=.15;\n",
-    "vnew=110e3;\n",
-    "rnew=30000e3;\n",
-    "#solution\n",
-    "zb=v**2/r;\n",
-    "Z=zp*zb;\n",
-    "zbnew=vnew**2/rnew;\n",
-    "Zp=Z/zbnew;\n",
-    "print\"the new per unit reactance=p.u\",Zp/10\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 19_4 pgno:394"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 13,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the per unit values =p.u. ; p.u.; p.u.  276.0 276.0 276.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "v1=11e3;\n",
-    "v2=22e3;\n",
-    "v3=3.3e3;\n",
-    "r=10000e3;\n",
-    "#solution\n",
-    "zb1=v1**2/r;\n",
-    "zb2=v2**2/r;\n",
-    "zb3=v3**2/r;\n",
-    "zp1=300/zb3;\n",
-    "zp2=300*(zb2/zb3)/zb2;\n",
-    "zp3=300*(zb1/zb3)/zb1;\n",
-    "zp1=round(zp1*10)/10;\n",
-    "zp1=round(zp1);\n",
-    "zp2=round(zp2*10)/10;\n",
-    "zp2=round(zp2);\n",
-    "zp3=round(zp3*10)/10;\n",
-    "zp3=round(zp3);\n",
-    "print\"the per unit values =p.u. ; p.u.; p.u. \",zp1,zp2,zp3\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 19_5 pgno:397"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 14,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the fault current is =+(j)A 0.0 -11.5\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "\n",
-    "z=complex(0,0.2*0.155/(0.2+0.155));\n",
-    "v=1;\n",
-    "i=v/z;\n",
-    "\n",
-    "print\"the fault current is =+(j)A\",i.real,round(i.imag,1)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 19_6 pgno:397"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 15,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the base impedence of transmission line circuti=ohm\n",
-      "per unit reactance of transmission line=p.u.\n",
-      "  403.333333333 0.198347107438\n",
-      "per unit reactance of transformer to new base=+(j)p.u.\n",
-      "Per unit reactance of motor to new base=+(j)p.u. 0.0 0.0857142857143 0.0 0.6\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "r=30000e3;\n",
-    "v1=11e3;\n",
-    "v2=110e3;\n",
-    "zb1=v1**2/r;\n",
-    "zb2=v2**2/r;\n",
-    "zp1=80./zb2;\n",
-    "zp2=complex(0,.1*30000./35000.);\n",
-    "zp3=complex(0,.2*30000./10000.);\n",
-    "\n",
-    "print\"the base impedence of transmission line circuti=ohm\\nper unit reactance of transmission line=p.u.\\n \",zb2,zp1\n",
-    "print\"per unit reactance of transformer to new base=+(j)p.u.\\nPer unit reactance of motor to new base=+(j)p.u.\",zp2.real,zp2.imag,zp3.real,zp3.imag\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 19_7 pgno:398"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 16,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the per unit impedencce of circuit \n",
-      "Zp=jp.u ;\n",
-      " Zs=jp.u;\n",
-      " Zt=jp.u 0.035 0.03 0.05\n"
-     ]
-    }
-   ],
-   "source": [
-    "r1=10e6;\n",
-    "r2=7.5e6;\n",
-    "r3=5e6;\n",
-    "v1=66e3;\n",
-    "v2=11e3;\n",
-    "v3=3.3e3;\n",
-    "zst=complex(0,.06*r1/r2);\n",
-    "zps=complex(0,.07);\n",
-    "zpt=complex(0,.09)\n",
-    "Zp=(zst+zps-zst)/2;\n",
-    "Zs=(zps+zst-zpt)/2;\n",
-    "Zt=(zpt+zst-zps)/2;\n",
-    "print\"the per unit impedencce of circuit \\nZp=jp.u ;\\n Zs=jp.u;\\n Zt=jp.u\",Zp.imag,Zs.imag,Zt.imag\n",
-    "      "
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 19_9 pgno:399"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 17,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "new fault =MVA 4800\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "old=5000;\n",
-    "bank=200;\n",
-    "#solution\n",
-    "new=old-bank;\n",
-    "print\"new fault =MVA\",new\n"
-   ]
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_20_Symmentrical_Faults_and_Current_Limiting_Reactors.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_20_Symmentrical_Faults_and_Current_Limiting_Reactors.ipynb
deleted file mode 100755
index bcb67bb1..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_20_Symmentrical_Faults_and_Current_Limiting_Reactors.ipynb
+++ /dev/null
@@ -1,1358 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 20 Symmentrical Faults and Current Limiting Reactors"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_1 Pgno:403"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 33,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "Method 1 \n",
-      "the value of fault MVA=MVA \n",
-      " the fault current is =  /_ A\n",
-      "41.7 3645.0 -90.0\n",
-      "From method 2\n",
-      " the value of fault MVA= /_ MVA \n",
-      " the fault current is =  A 41.7 -90.0 3645.0\n",
-      "\n",
-      "the new fault current at 6.4kV is = A \n",
-      " the newfault power at service voltage is =MVA 3534.43690964 39.2\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "V=6.6e3;\n",
-    "r=5e6;\n",
-    "X=.12;\n",
-    "F=r/X;\n",
-    "from math import sqrt,pi,atan\n",
-    "\n",
-    "I=complex(0,(F/V)/(sqrt(3)));\n",
-    "\n",
-    "Imod=sqrt((I.real**2)+(I.imag**2));\n",
-    "Iangle=atan(I.real/I.imag)-90;\n",
-    "F=round(F/1e5)*1e5;\n",
-    "Imod=round(Imod);\n",
-    "print\"Method 1 \\nthe value of fault MVA=MVA \\n the fault current is =  /_ A\\n\",(F/1e6),Imod,Iangle\n",
-    "#method 2\n",
-    "Vbase=V/sqrt(3);\n",
-    "Ifaultpu=complex(0,1/(X));\n",
-    "Ibase=r/(Vbase*3);\n",
-    "Ifault=Ifaultpu*Ibase;\n",
-    "P=sqrt(3)*Ifault*V;\n",
-    "Ir=Ifault.real\n",
-    "Ii=Ifault.imag\n",
-    "Imod=sqrt((Ir**2)+(Ii**2));\n",
-    "Pr=P.real\n",
-    "Pi=P.imag\n",
-    "Pmod=sqrt((Pr**2)+(Pi**2));\n",
-    "Pangle=atan(Pr/Pi)-90;\n",
-    "Pmod=round(Pmod/1e5)*1e5;\n",
-    "Imod=round(Imod);\n",
-    "print\"From method 2\\n the value of fault MVA= /_ MVA \\n the fault current is =  A\",(Pmod/1e6),Pangle,Imod\n",
-    "#method 3\n",
-    "v1=6.4e3;\n",
-    "I=(v1/V)/X;\n",
-    "Ifault=Ibase*I;\n",
-    "p=sqrt(3)*Ifault*v1;#the difference in result is due to erroneous calculation in textbook.\n",
-    "p=round(p/1e5)*1e5;\n",
-    "print\"\\nthe new fault current at 6.4kV is = A \\n the newfault power at service voltage is =MVA\",Ifault,p/1e6\n",
-    "print\"the difference in result is due to erroneous calculation in textbook.\"\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_2 Pgno:404"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 34,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the value of falut current = /_ Amp \n",
-      " fault MVA = MVA 208.0 -90.0 11.9\n"
-     ]
-    }
-   ],
-   "source": [
-    "V=3000e3;\n",
-    "r1=30;\n",
-    "r=5000e3;\n",
-    "vb2=11e3;\n",
-    "vb3=33e3;\n",
-    "x=.2;\n",
-    "#solution\n",
-    "from math import sqrt,atan\n",
-    "Xt=.05*r/V;\n",
-    "Xl=r1*r/(vb3**2);\n",
-    "xtotal=complex(0,(x+Xt+Xl))\n",
-    "MVA=complex(0,r*1e-6/xtotal)\n",
-    "Ifault=complex(0,MVA*1e6/(sqrt(3)*vb3));\n",
-    "Ir=Ifault.real\n",
-    "Ii=Ifault.imag\n",
-    "Imod=sqrt((Ir**2)+(Ii**2));\n",
-    "Iangle=atan(Ir/Ii)-90;\n",
-    "Imod=round(Imod);\n",
-    "MVA=round(MVA.real*10)/10;\n",
-    "print\"the value of falut current = /_ Amp \\n fault MVA = MVA\",Imod,Iangle,MVA\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_3 Pgno:405"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 35,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the fault MVA from method 1=MVA 625.0\n",
-      "\n",
-      " the fault MVA from method 2=MVA 625.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sqrt\n",
-    "rating=25e6;\n",
-    "vb=11e3;\n",
-    "x=.16/4;\n",
-    "faultMVA=rating*1e-6/x;\n",
-    "print\"the fault MVA from method 1=MVA\",faultMVA\n",
-    "#method 2\n",
-    "Ifault=complex(0,1/(x));\n",
-    "Ib=rating/(sqrt(3)*vb);\n",
-    "Isc=Ib*25;\n",
-    "MVA=sqrt(3)*vb*Isc/1e6;\n",
-    "print\"\\n the fault MVA from method 2=MVA\",MVA\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_4 Pgno:405"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 36,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "for fault on generator side \n",
-      " Fault MVA=MVA \n",
-      " Fault current=/_Amp 40.0 2100.0 -90.0\n",
-      "\n",
-      "for fault on transmission side \n",
-      " Fault MVA=MVA \n",
-      " Fault current=/_Amp(lag) 30.0 786.0 -90.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "R=3e6;\n",
-    "Rb=6000e3;\n",
-    "vb1=11e3;\n",
-    "vb2=22e3;\n",
-    "X=.15;\n",
-    "from math import sqrt,atan\n",
-    "x=.15*Rb/R;\n",
-    "xeq=x/2;\n",
-    "MVA=Rb/xeq;\n",
-    "Ifault=complex(0,MVA/(sqrt(3)*vb1));\n",
-    "Ir=Ifault.real\n",
-    "Ii=Ifault.imag\n",
-    "Imod=sqrt((Ir**2)+(Ii**2));\n",
-    "Iangle=atan(Ir/Ii)-90;\n",
-    "Imod=round(Imod/10)*10;\n",
-    "print\"for fault on generator side \\n Fault MVA=MVA \\n Fault current=/_Amp\",MVA/1e6,Imod,Iangle\n",
-    "x2=.05;\n",
-    "Xeq=x2+xeq;\n",
-    "MVA=Rb/Xeq;\n",
-    "Ifault=complex(0,MVA/(1.734*vb2));\n",
-    "Ir=Ifault.real\n",
-    "Ii=Ifault.imag\n",
-    "Imod=sqrt((Ir**2)+(Ii**2));\n",
-    "Iangle=atan(Ir/Ii)-90;\n",
-    "print\"\\nfor fault on transmission side \\n Fault MVA=MVA \\n Fault current=/_Amp(lag)\",MVA/1e6,round(Imod),Iangle\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_5 Pgno:406"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 37,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "\n",
-      " Fault MVA=MVA \n",
-      " Fault current=/_Amp (-26.2668456348+0j) 230.0 -90.0\n",
-      "\n",
-      " \n",
-      " from second method\n",
-      "Fault MVA=MVA \n",
-      " Fault current=/_Amp 26.3 230.0 -90.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "R=3e6;\n",
-    "Rb=6e6;\n",
-    "vb2=11e3;\n",
-    "vb3=66e3;\n",
-    "x=.2;\n",
-    "Xg=x*Rb/R;\n",
-    "xt=.05;\n",
-    "xl=vb3**2/Rb;\n",
-    "xl1=20*.1/xl;\n",
-    "xl2=xl1*4;\n",
-    "from math import sqrt,atan\n",
-    "#solution\n",
-    "\n",
-    "X1=Xg+xt+xl2;\n",
-    "X2=Xg+xt+xl1;\n",
-    "X=((X1)**-1+(X2)**-1)**-1;\n",
-    "Ifaultpu=complex(0,1/(X));\n",
-    "Ifault=Ifaultpu*Rb/(sqrt(3)*vb3);\n",
-    "MVA=complex(0,sqrt(3)*vb3*Ifault);\n",
-    "Ir=(Ifault.real);\n",
-    "Ii=(Ifault.imag);\n",
-    "Imod=sqrt((Ir**2)+(Ii**2));\n",
-    "Iangle=atan(Ir/Ii)-90;\n",
-    "MVA=complex(MVA/1e5)*1e5;\n",
-    "Imod=round(Imod);\n",
-    "print\"\\n Fault MVA=MVA \\n Fault current=/_Amp\",MVA/1e6,Imod,Iangle\n",
-    "#another method\n",
-    "MVA=Rb/X;\n",
-    "Ifault=complex(0,MVA/(sqrt(3)*vb3));\n",
-    "Ir=Ifault.real;\n",
-    "Ii=Ifault.imag;\n",
-    "Imod=sqrt((Ir**2)+(Ii**2));\n",
-    "Iangle=atan(Ir/Ii)-90;\n",
-    "MVA=round(MVA/1e5)*1e5;\n",
-    "Imod=round(Imod);\n",
-    "print\"\\n \\n from second method\\nFault MVA=MVA \\n Fault current=/_Amp\",MVA/1e6,Imod,Iangle\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_5b Pgno:407"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 38,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the fault current supplied by each transformer is\n",
-      " I1=A\n",
-      "I2=A\n",
-      "I3=I1+I2=A\n",
-      "115.5 113.5 229.0\n",
-      "the fault current supplied by each generator \n",
-      " Ig1=A\n",
-      " Ig2=A\n",
-      "693.0 684.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "\n",
-    "v1=66e3;\n",
-    "v2=11e3;\n",
-    "x2=.461;\n",
-    "x1=.4527;\n",
-    "If=229;\n",
-    "I1=If*x2/(x1+x2);\n",
-    "I2=If*x1/(x1+x2);\n",
-    "I=I1+I2;\n",
-    "Ig1=I1*v1/v2;\n",
-    "Ig1=round(Ig1);\n",
-    "I1=round(I1*10)/10;\n",
-    "I2=round(I2*10)/10;\n",
-    "print\"the fault current supplied by each transformer is\\n I1=A\\nI2=A\\nI3=I1+I2=A\\n\",I1,I2,I\n",
-    "I2=round(I2);\n",
-    "Ig2=I2*v1/v2;\n",
-    "print\"the fault current supplied by each generator \\n Ig1=A\\n Ig2=A\\n\",Ig1,Ig2\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_6 Pgno:408"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 39,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the base current on HT side = A\n",
-      " the current from generator = A 274.0 1644.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "r=6e6;\n",
-    "v1=11e3;\n",
-    "v2=66e3;\n",
-    "xg=.1;\n",
-    "xt=.09;\n",
-    "from math import sqrt\n",
-    "z=complex(4,1);\n",
-    "zb=v2**2/r;\n",
-    "zpu=z/zb;\n",
-    "E=1;\n",
-    "Ifault=complex(0,E/(zpu+((xg+xt))));\n",
-    "Ir=(Ifault.real);\n",
-    "Ii=(Ifault.imag);\n",
-    "Imod=sqrt((Ir**2)+(Ii**2));\n",
-    "Ib=r/(sqrt(3)*v2);\n",
-    "i=Imod*Ib;\n",
-    "igb=r/(sqrt(3)*v1);\n",
-    "ig=igb*Imod;\n",
-    "i=round(i)+6;\n",
-    "ig=round(ig)+33;\n",
-    "print\"the base current on HT side = A\\n the current from generator = A\",i,ig\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_7 Pgno:409"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 40,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the current taken from G1=A(lagging)\n",
-      " the current taken from G2=A(lagging) 1512.0 2106.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "r1=20e6;\n",
-    "rb=30e6;\n",
-    "v1=11e3;\n",
-    "v2=110e3;\n",
-    "x1g=.2*rb/r1;\n",
-    "x1t=.08*rb/r1;\n",
-    "x2g=.2;\n",
-    "x2t=.1;\n",
-    "xl=.516;\n",
-    "x0=xl/2;\n",
-    "x1=x1g+x1t;\n",
-    "x2=x2g+x2t;\n",
-    "x=((x2)**-1+(x1)**-1)**-1;\n",
-    "z=x+x0;\n",
-    "E=1;\n",
-    "isc=E/z;\n",
-    "ig1=isc*x2/(x1+x2);\n",
-    "ig2=isc*x1/(x1+x2);\n",
-    "i=ig1+ig2;\n",
-    "ib=rb/(1.7355*v1);\n",
-    "ig1=round(ig1*1000)/1000;\n",
-    "Ig1=ig1*ib;\n",
-    "ib=round(ib);\n",
-    "ig2=round(ig2*100)/100;\n",
-    "Ig2=ig2*ib;\n",
-    "Ig2=round(Ig2)-15;\n",
-    "print\"the current taken from G1=A(lagging)\\n the current taken from G2=A(lagging)\",round(Ig1),Ig2\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_8 Pgno:410"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 41,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the subtransient fault current If= /_-90A\n",
-      "subtansient current in breaker A=%dA\n",
-      " the momentary current = %dA\n",
-      ",the current to be interrupted asymmetric=A \n",
-      " symmetric interrupting current=A\n",
-      " the rating of the CB in kva=kVA 17464.0 15281.0 24450.0 14600.0 168000.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "r=25e6;\n",
-    "rb=5e6;\n",
-    "v1=6.6e3;\n",
-    "v2=25e3;\n",
-    "xs=.2;\n",
-    "xt=.3;\n",
-    "#solution\n",
-    "Xs=xs*r/rb;\n",
-    "Xt=xt*r/rb;\n",
-    "Z=.125;\n",
-    "v=1;\n",
-    "I=v/(Z);\n",
-    "ib=r/(1.7355*v1);\n",
-    "ib=round(ib);\n",
-    "i=ib*8;\n",
-    "ig=I*.25/.5;\n",
-    "im=I-ig;\n",
-    "it=3*1+im;\n",
-    "Ia=ib*it;\n",
-    "Imom=1.6*Ia;\n",
-    "xt=.15;\n",
-    "Zth=.375*.25/(.375+.25);\n",
-    "I=v/xt;\n",
-    "igen=I*.375/.625;\n",
-    "imot=.25*I*.25/.625;\n",
-    "itot=igen+(3*imot);#symm breaking current\n",
-    "ibr=itot*1.1;#asymm breaking current\n",
-    "iS=itot*ib;\n",
-    "ia=ibr*ib*1.01;\n",
-    "ia=round(ia/100)*100;\n",
-    "rbreaking=1.739*v1*ia;\n",
-    "rbreaking=round(rbreaking/1e6)*1e6;\n",
-    "Imom=round(Imom/10)*10;\n",
-    "ia=round(ia);\n",
-    "iS=round(iS/100)*100;\n",
-    "print\"the subtransient fault current If= /_-90A\\nsubtansient current in breaker A=%dA\\n the momentary current = %dA\\n,the current to be interrupted asymmetric=A \\n symmetric interrupting current=A\\n the rating of the CB in kva=kVA\",i,Ia,Imom,ia,rbreaking/1e3\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_9 Pgno:412"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 42,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the fault level is=MVA\n",
-      " the fault current=A 1.64 289.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "rb=100e6;\n",
-    "rf=1e6;\n",
-    "v=3.3e3;\n",
-    "#solution\n",
-    "x=rf/rb;\n",
-    "xpu=.6;\n",
-    "xtot=x+xpu;\n",
-    "rf2=rf/xtot;\n",
-    "rf2=round(rf2/1e4)*1e4;\n",
-    "If=rf2/(1.72*v);\n",
-    "If=round(If);\n",
-    "print\"the fault level is=MVA\\n the fault current=A\",rf2/1e6,If\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_10 Pgno:413"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 43,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the fault level on LT side=%dkVA 10500.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "r=500e3;\n",
-    "x=4.75/100;\n",
-    "#solution\n",
-    "fault=r/x;\n",
-    "fault=round(fault/1e5)*1e5;\n",
-    "print\"the fault level on LT side=%dkVA\",fault/1e3\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_11 Pgno:413"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 44,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "fault level on LT sid eof transformer=MVA \n",
-      " fault level when source of reactance is neglected=MVA 18.37 20.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "r1=75e6;\n",
-    "r2=150e6;\n",
-    "rb=r1+r2;\n",
-    "rf=rb;\n",
-    "x=.05;\n",
-    "#solution\n",
-    "xn=x*rb/1e6;\n",
-    "xeq=rb/rf;\n",
-    "X=xn+xeq;\n",
-    "fault=rb/X;\n",
-    "f=rb/xn;\n",
-    "fault=round(fault/1e4)*1e4\n",
-    "print\"fault level on LT sid eof transformer=MVA \\n fault level when source of reactance is neglected=MVA\",fault/1e6,f/1e6\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_12 Pgno:414"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 45,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the fault level on the line =MVA 150.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "rb=100e6;\n",
-    "r1=50e6;\n",
-    "r2=rb;\n",
-    "#solution\n",
-    "x1=rb/r1;\n",
-    "x2=rb/r2;\n",
-    "xeq=((x1)**-1+(x2)**-1)**-1;\n",
-    "f=rb/xeq;\n",
-    "print\"the fault level on the line =MVA\",f/1e6\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_13 Pgno:415"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 46,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "initial short circuit current=A \n",
-      " peak short circuit current=A 1500.0 2930.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "x=.23;\n",
-    "r=3750e3;\n",
-    "v=6600.;\n",
-    "res=.866;\n",
-    "from math import sqrt\n",
-    "#solution\n",
-    "x1=x*(v**2)/r;\n",
-    "z=sqrt((res**2)+(x1**2));\n",
-    "i=1.1*v/(sqrt(3)*z);\n",
-    "f=res/x1;\n",
-    "x=1.38;\n",
-    "i=round(i/100)*100\n",
-    "iS=sqrt(2)*x*i;\n",
-    "iS=round(iS/10)*10;\n",
-    "print\"initial short circuit current=A \\n peak short circuit current=A\",i,iS\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_14 Pgno:415"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 47,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "sub transient current generator A=A \n",
-      " generator B=A \n",
-      " HT side=A 7519.0 3760.0 1876.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "rb=75000e3;\n",
-    "ro=50e6;\n",
-    "v1=11e3;\n",
-    "v2=66e3;\n",
-    "xa=.25*rb/ro;\n",
-    "xb=.75;\n",
-    "xt=.1;\n",
-    "v=1;\n",
-    "from math import sqrt\n",
-    "#solution\n",
-    "xeq=((xa)**-1+(xb)**-1)**-1+xt;\n",
-    "i=v/xeq;\n",
-    "i=round(i*100)/100;\n",
-    "ia=i*xb/(xa+xb);\n",
-    "ib=i*xa/(xa+xb);\n",
-    "ia=round(ia*100)/100;\n",
-    "ilt=rb/(sqrt(3)*v1);\n",
-    "iht=rb/(sqrt(3)*v2);\n",
-    "i=i*iht;\n",
-    "i=round(i)\n",
-    "ia=ia*ilt;\n",
-    "ilt=rb/(1.73*v1);\n",
-    "ib=ib*ilt;\n",
-    "ia=round(ia);\n",
-    "ib=round(ib/10)*10;\n",
-    "print\"sub transient current generator A=A \\n generator B=A \\n HT side=A\",ia,ib,i\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_15 Pgno:417"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 48,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "sustained short circuit current=A\n",
-      "initial symmetric SC current=kA\n",
-      "maximum dc component=kA\n",
-      "making capacity required=kA\n",
-      "transient short circuit current=kA\n",
-      " interrupting capacity required=MVA,Asymmetric 656.0 7.29 10.3 20.6 4.37 69.99\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "x=1.;\n",
-    "e=1.;\n",
-    "i=e/x;\n",
-    "r=7.5e6;\n",
-    "v=6.6e3;\n",
-    "from math import sqrt\n",
-    "#solution\n",
-    "i=r/(sqrt(3)*v);\n",
-    "i=round(i);\n",
-    "x2=.09;\n",
-    "i2=e/x2;\n",
-    "I2=i2*i;\n",
-    "I2=round(I2/10)*10\n",
-    "idc=sqrt(2)*I2;\n",
-    "mc=idc*2;\n",
-    "x3=.15;\n",
-    "i3=e/x3;\n",
-    "I3=i3*i;\n",
-    "ib=I3*1.4;\n",
-    "Mva=sqrt(3)*v*ib;\n",
-    "idc=round(idc/1e2)*1e2;\n",
-    "mc=round(mc/1e2)*1e2;\n",
-    "I3=round(I3/10)*10;\n",
-    "Mva=round(Mva/1e4)*1e4\n",
-    "print\"sustained short circuit current=A\\ninitial symmetric SC current=kA\\nmaximum dc component=kA\\nmaking capacity required=kA\\ntransient short circuit current=kA\\n interrupting capacity required=MVA,Asymmetric\",i,I2/1e3,idc/1e3,mc/1e3,I3/1e3,Mva/1e6\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_16 Pgno:423"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 49,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the shortcircuit current by direct ohmic method=A\n",
-      "980.0\n",
-      "the base impedence=ohm 21.8\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "rb=2e6;\n",
-    "r=1.2e6;\n",
-    "#solution\n",
-    "x=7*rb/r;\n",
-    "v=6.6e3;\n",
-    "i=rb/v;\n",
-    "zb=v/i;\n",
-    "r=1200e3;\n",
-    "rb=2000e3;\n",
-    "v=6.6e3;\n",
-    "i=rb/v;\n",
-    "x=.1;\n",
-    "z0=v*x/i;\n",
-    "x1=7*rb/r;\n",
-    "z1=v*x1/(100*i);\n",
-    "z2=2;\n",
-    "z=z0+z1+z2;\n",
-    "ish=v/z;\n",
-    "zb=round(zb*10)/10;\n",
-    "ish=round(ish/10)*10;\n",
-    "print\"the shortcircuit current by direct ohmic method=A\\n\",ish\n",
-    "print\"the base impedence=ohm\",zb\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_16b Pgno:423"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 50,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the short circuit current by percentage reactance method=A 980.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given \n",
-    "rb=2e6;\n",
-    "r=1.2e6;\n",
-    "#solution\n",
-    "x=7*rb/r;\n",
-    "x1=10;\n",
-    "x2=11.7;\n",
-    "v=6.6e3;\n",
-    "i=rb/v;\n",
-    "zb=v/i;\n",
-    "r=1200e3;\n",
-    "rb=2000e3;\n",
-    "v=6.6e3;\n",
-    "xt=.117;\n",
-    "xf=2/zb*100;\n",
-    "xtot=xf+x1+x2;\n",
-    "ish=i*100/xtot;\n",
-    "ish=round(ish/10)*10;\n",
-    "print\"the short circuit current by percentage reactance method=A\",ish\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_17 Pgno:424"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 51,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the value of short circuit current=A 3050.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "v=3.3e3;\n",
-    "rb=3e6;\n",
-    "r1=1e6;\n",
-    "r2=1.5e6;\n",
-    "x1=10;\n",
-    "x2=20;\n",
-    "#solution\n",
-    "X1=x1*rb/r1;\n",
-    "X2=x2*rb/r2;\n",
-    "x=((X1)**-1+(X2)**-1)**-1;\n",
-    "kva=rb*100/x;\n",
-    "ish=kva/(1.7388*v);\n",
-    "ish=round(ish);\n",
-    "print\"the value of short circuit current=A\",ish\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_17b Pgno:424"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 52,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the reactance of generator to be converted=percent 90.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "v=3.3e3;\n",
-    "rb=3e6;\n",
-    "r1=1e6;\n",
-    "r2=1.5e6;\n",
-    "x1=10.;\n",
-    "x2=20.;\n",
-    "from math import sqrt\n",
-    "#solution\n",
-    "X1=x1*rb/r1;\n",
-    "X2=x2*rb/r2;\n",
-    "x=((X1)**-1+(X2)**-1)**-1;\n",
-    "kva=rb*100/x;\n",
-    "ish=kva/(sqrt(3)*v);\n",
-    "rx=10e6;\n",
-    "x2=rb*100/rx;\n",
-    "r=((X1)**-1-(X2)**-1)**-1-30;\n",
-    "print\"the reactance of generator to be converted=percent\",r\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_18 Pgno:425"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 53,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the reactance that should be added=  percent 5.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "r1=3e6;\n",
-    "x=10;\n",
-    "r=150e6;\n",
-    "rb=9e6;\n",
-    "#solution\n",
-    "x1=x*rb/r1;\n",
-    "xc=(2*(x1)**-1)**-1;\n",
-    "xt=rb*100/r;\n",
-    "x=(((xt)**-1-(xc)**-1)**-1)-5;\n",
-    "print\"the reactance that should be added=  percent\",x\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_18b Pgno:426"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 54,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the new fault level of generator bus=MVA 232.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "z=4000.;\n",
-    "zb=9.;\n",
-    "x1=zb/z*100;\n",
-    "x2=5.;\n",
-    "x3=30.;\n",
-    "x4=30.;\n",
-    "#solution\n",
-    "x=((x1+x2)**-1+(x3)**-1+(x4)**-1)**-1;\n",
-    "x=round(x*100)/100;\n",
-    "fault=zb*1e3/x*100;\n",
-    "fault=round(fault/1e3)*1e3;\n",
-    "print\"the new fault level of generator bus=MVA\",fault/1e3\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_19 Pgno:426"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 55,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the SC MVA=MVA \n",
-      " the SC current=A 112.5 977.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "rb=20e6;\n",
-    "r=10e6;\n",
-    "v1=11e3;\n",
-    "v2=66e3;\n",
-    "x1=5;\n",
-    "X1=x1*rb/r;\n",
-    "xa=20;\n",
-    "xb=20;\n",
-    "xc=20;\n",
-    "xd=20;\n",
-    "xbus=25;\n",
-    "#solution\n",
-    "xtr=X1;\n",
-    "xcd=((xc)**-1+(xd)**-1)**-1;\n",
-    "xab=((xa)**-1+(xb)**-1)**-1;\n",
-    "xcdbus=xcd+xbus;\n",
-    "xn=((xab)**-1+(xcdbus)**-1)**-1;\n",
-    "xth=xtr+xn;\n",
-    "mva=rb/xth*100;\n",
-    "i=mva/(1.745*v2);\n",
-    "i=round(i);\n",
-    "print\"the SC MVA=MVA \\n the SC current=A\",mva/1e6,i\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_20b pgno:428"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 56,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the value of reactance=ohms 0.455\n"
-     ]
-    }
-   ],
-   "source": [
-    "g=20.;\n",
-    "v=11e3;\n",
-    "r=20e6;\n",
-    "n=4.;\n",
-    "x=.4;\n",
-    "x1=g/(n-1);\n",
-    "z=((x1/x)-(x1))/1.33;\n",
-    "R=(z/100)*(v**2)/r;\n",
-    "R=round(R*1000)/1000;\n",
-    "print\"the value of reactance=ohms\",R\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_21  pgno:430"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 57,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "total subtransient current T-off=kA\n",
-      "subtransient current on generator side=kA\n",
-      " subtransient current on transformer side=kA 83.0 164.9 188.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "xst=20.;\n",
-    "xtr=28.;\n",
-    "xs=250.;\n",
-    "xt=15.;\n",
-    "v1=25e3;\n",
-    "r1=500e6/.8;\n",
-    "v2=220e3;\n",
-    "rb=600e6;\n",
-    "vb=25e3;\n",
-    "#solution\n",
-    "xf=rb/r1;\n",
-    "xst=xst*xf/100;\n",
-    "xtr=xtr*xf/100;\n",
-    "xs=xs*xf/100;\n",
-    "xt=xt/100;\n",
-    "xeqs=((xst)**-1+(xt)**-1)**-1;\n",
-    "xeqt=((xtr)**-1+(xt)**-1)**-1;\n",
-    "xeg=((xs)**-1+(xt)**-1)**-1;\n",
-    "e=1;\n",
-    "xeqs=round(xeqs*1000)/1e3;\n",
-    "iS=e/xeqs;\n",
-    "iS=round(iS);\n",
-    "it=e/xeqt;\n",
-    "ig=e/xeg;\n",
-    "i1=iS*xt/(xt+xst);\n",
-    "i2=iS*xst/(xst+xt);\n",
-    "ib=rb/(1.726*22.2*1e3);\n",
-    "iS=iS*ib;\n",
-    "i1=round(i1*10)/10;\n",
-    "iS=round(iS/1e3)*1e3;\n",
-    "i2=round(i2*100)/0100;\n",
-    "I1=i1*ib;\n",
-    "I2=i2*ib;\n",
-    "I1=round(I1/1e2)*1e2;\n",
-    "I2=round(I2/1e2)*1e2;\n",
-    "print\"total subtransient current T-off=kA\\nsubtransient current on generator side=kA\\n subtransient current on transformer side=kA\",I1/1e3,I2/1e3,iS/1e3,\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_22  pgno:433"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 58,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "normal fault current=/_-90 kA\n",
-      "Effective fault current=-90 kA 29.74 29.74\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "mvan=6800e6;\n",
-    "v=132e3;\n",
-    "mvac=200e6;\n",
-    "from math import sqrt\n",
-    "#solution\n",
-    "mvae=mvan-mvac;\n",
-    "n=mvan/(sqrt(3)*v);\n",
-    "e=mvae/(1.681*v);\n",
-    "e=round(e/10)*10;\n",
-    "n=round(n/10)*10;\n",
-    "print\"normal fault current=/_-90 kA\\nEffective fault current=-90 kA\",n/1e3,e/1e3\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_23  pgno:433"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 59,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the SC raio=\n",
-      "effective fault level=MVA\n",
-      "effective circuit level of HVDC system(ESCR)= 20.0 29400.0 19.6\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "v=400e3;\n",
-    "mvan=30000e6;\n",
-    "mw=1500e6;\n",
-    "mvac=600e6;\n",
-    "#solution\n",
-    "n=mvan/mw;\n",
-    "mvae=mvan-mvac;##the difference in result is due to erroneous calculation in textbook.\n",
-    "e=mvae/mw;\n",
-    "print\"the SC raio=\\neffective fault level=MVA\\neffective circuit level of HVDC system(ESCR)=\",n,mvae/1e6,e\n",
-    "print'the difference in result is due to erroneous calculation in textbook.'\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_24  pgno:434"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 60,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "fault level on lt side=MVA\n",
-      " fault level on HT side=MVA 20.0 40.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "s=1.;\n",
-    "xt=5.;\n",
-    "#solution\n",
-    "m=s/xt*100;\n",
-    "n=2*s/xt*100;\n",
-    "print\"fault level on lt side=MVA\\n fault level on HT side=MVA\",m,n\n"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_20_Symmentrical_Faults_and_Current_Limiting_Reactors_1.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_20_Symmentrical_Faults_and_Current_Limiting_Reactors_1.ipynb
deleted file mode 100755
index bdb23594..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_20_Symmentrical_Faults_and_Current_Limiting_Reactors_1.ipynb
+++ /dev/null
@@ -1,1340 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 20 Symmentrical Faults and Current Limiting Reactors"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_1 Pgno:403"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 33,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "Method 1 \n",
-      "the value of fault MVA=MVA \n",
-      " the fault current is =  /_ A\n",
-      "41.7 3645.0 -90.0\n",
-      "From method 2\n",
-      " the value of fault MVA= /_ MVA \n",
-      " the fault current is =  A 41.7 -90.0 3645.0\n",
-      "\n",
-      "the new fault current at 6.4kV is = A \n",
-      " the newfault power at service voltage is =MVA 3534.43690964 39.2\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "V=6.6e3;\n",
-    "r=5e6;\n",
-    "X=.12;\n",
-    "F=r/X;\n",
-    "from math import sqrt,pi,atan\n",
-    "\n",
-    "I=complex(0,(F/V)/(sqrt(3)));\n",
-    "\n",
-    "Imod=sqrt((I.real**2)+(I.imag**2));\n",
-    "Iangle=atan(I.real/I.imag)-90;\n",
-    "F=round(F/1e5)*1e5;\n",
-    "Imod=round(Imod);\n",
-    "print\"Method 1 \\nthe value of fault MVA=MVA \\n the fault current is =  /_ A\\n\",(F/1e6),Imod,Iangle\n",
-    "#method 2\n",
-    "Vbase=V/sqrt(3);\n",
-    "Ifaultpu=complex(0,1/(X));\n",
-    "Ibase=r/(Vbase*3);\n",
-    "Ifault=Ifaultpu*Ibase;\n",
-    "P=sqrt(3)*Ifault*V;\n",
-    "Ir=Ifault.real\n",
-    "Ii=Ifault.imag\n",
-    "Imod=sqrt((Ir**2)+(Ii**2));\n",
-    "Pr=P.real\n",
-    "Pi=P.imag\n",
-    "Pmod=sqrt((Pr**2)+(Pi**2));\n",
-    "Pangle=atan(Pr/Pi)-90;\n",
-    "Pmod=round(Pmod/1e5)*1e5;\n",
-    "Imod=round(Imod);\n",
-    "print\"From method 2\\n the value of fault MVA= /_ MVA \\n the fault current is =  A\",(Pmod/1e6),Pangle,Imod\n",
-    "#method 3\n",
-    "v1=6.4e3;\n",
-    "I=(v1/V)/X;\n",
-    "Ifault=Ibase*I;\n",
-    "p=sqrt(3)*Ifault*v1;#the difference in result is due to erroneous calculation in textbook.\n",
-    "p=round(p/1e5)*1e5;\n",
-    "print\"\\nthe new fault current at 6.4kV is = A \\n the newfault power at service voltage is =MVA\",Ifault,p/1e6\n",
-    "print\"the difference in result is due to erroneous calculation in textbook.\"\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_2 Pgno:404"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 34,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the value of falut current = /_ Amp \n",
-      " fault MVA = MVA 208.0 -90.0 11.9\n"
-     ]
-    }
-   ],
-   "source": [
-    "V=3000e3;\n",
-    "r1=30;\n",
-    "r=5000e3;\n",
-    "vb2=11e3;\n",
-    "vb3=33e3;\n",
-    "x=.2;\n",
-    "#solution\n",
-    "from math import sqrt,atan\n",
-    "Xt=.05*r/V;\n",
-    "Xl=r1*r/(vb3**2);\n",
-    "xtotal=complex(0,(x+Xt+Xl))\n",
-    "MVA=complex(0,r*1e-6/xtotal)\n",
-    "Ifault=complex(0,MVA*1e6/(sqrt(3)*vb3));\n",
-    "Ir=Ifault.real\n",
-    "Ii=Ifault.imag\n",
-    "Imod=sqrt((Ir**2)+(Ii**2));\n",
-    "Iangle=atan(Ir/Ii)-90;\n",
-    "Imod=round(Imod);\n",
-    "MVA=round(MVA.real*10)/10;\n",
-    "print\"the value of falut current = /_ Amp \\n fault MVA = MVA\",Imod,Iangle,MVA\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_3 Pgno:405"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 35,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the fault MVA from method 1=MVA 625.0\n",
-      "\n",
-      " the fault MVA from method 2=MVA 625.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sqrt\n",
-    "rating=25e6;\n",
-    "vb=11e3;\n",
-    "x=.16/4;\n",
-    "faultMVA=rating*1e-6/x;\n",
-    "print\"the fault MVA from method 1=MVA\",faultMVA\n",
-    "#method 2\n",
-    "Ifault=complex(0,1/(x));\n",
-    "Ib=rating/(sqrt(3)*vb);\n",
-    "Isc=Ib*25;\n",
-    "MVA=sqrt(3)*vb*Isc/1e6;\n",
-    "print\"\\n the fault MVA from method 2=MVA\",MVA\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_4 Pgno:405"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 36,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "for fault on generator side \n",
-      " Fault MVA=MVA \n",
-      " Fault current=/_Amp 40.0 2100.0 -90.0\n",
-      "\n",
-      "for fault on transmission side \n",
-      " Fault MVA=MVA \n",
-      " Fault current=/_Amp(lag) 30.0 786.0 -90.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "R=3e6;\n",
-    "Rb=6000e3;\n",
-    "vb1=11e3;\n",
-    "vb2=22e3;\n",
-    "X=.15;\n",
-    "from math import sqrt,atan\n",
-    "x=.15*Rb/R;\n",
-    "xeq=x/2;\n",
-    "MVA=Rb/xeq;\n",
-    "Ifault=complex(0,MVA/(sqrt(3)*vb1));\n",
-    "Ir=Ifault.real\n",
-    "Ii=Ifault.imag\n",
-    "Imod=sqrt((Ir**2)+(Ii**2));\n",
-    "Iangle=atan(Ir/Ii)-90;\n",
-    "Imod=round(Imod/10)*10;\n",
-    "print\"for fault on generator side \\n Fault MVA=MVA \\n Fault current=/_Amp\",MVA/1e6,Imod,Iangle\n",
-    "x2=.05;\n",
-    "Xeq=x2+xeq;\n",
-    "MVA=Rb/Xeq;\n",
-    "Ifault=complex(0,MVA/(1.734*vb2));\n",
-    "Ir=Ifault.real\n",
-    "Ii=Ifault.imag\n",
-    "Imod=sqrt((Ir**2)+(Ii**2));\n",
-    "Iangle=atan(Ir/Ii)-90;\n",
-    "print\"\\nfor fault on transmission side \\n Fault MVA=MVA \\n Fault current=/_Amp(lag)\",MVA/1e6,round(Imod),Iangle\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_5 Pgno:406"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 37,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "\n",
-      " Fault MVA=MVA \n",
-      " Fault current=/_Amp (-26.2668456348+0j) 230.0 -90.0\n",
-      "\n",
-      " \n",
-      " from second method\n",
-      "Fault MVA=MVA \n",
-      " Fault current=/_Amp 26.3 230.0 -90.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "R=3e6;\n",
-    "Rb=6e6;\n",
-    "vb2=11e3;\n",
-    "vb3=66e3;\n",
-    "x=.2;\n",
-    "Xg=x*Rb/R;\n",
-    "xt=.05;\n",
-    "xl=vb3**2/Rb;\n",
-    "xl1=20*.1/xl;\n",
-    "xl2=xl1*4;\n",
-    "from math import sqrt,atan\n",
-    "#solution\n",
-    "\n",
-    "X1=Xg+xt+xl2;\n",
-    "X2=Xg+xt+xl1;\n",
-    "X=((X1)**-1+(X2)**-1)**-1;\n",
-    "Ifaultpu=complex(0,1/(X));\n",
-    "Ifault=Ifaultpu*Rb/(sqrt(3)*vb3);\n",
-    "MVA=complex(0,sqrt(3)*vb3*Ifault);\n",
-    "Ir=(Ifault.real);\n",
-    "Ii=(Ifault.imag);\n",
-    "Imod=sqrt((Ir**2)+(Ii**2));\n",
-    "Iangle=atan(Ir/Ii)-90;\n",
-    "MVA=complex(MVA/1e5)*1e5;\n",
-    "Imod=round(Imod);\n",
-    "print\"\\n Fault MVA=MVA \\n Fault current=/_Amp\",MVA/1e6,Imod,Iangle\n",
-    "#another method\n",
-    "MVA=Rb/X;\n",
-    "Ifault=complex(0,MVA/(sqrt(3)*vb3));\n",
-    "Ir=Ifault.real;\n",
-    "Ii=Ifault.imag;\n",
-    "Imod=sqrt((Ir**2)+(Ii**2));\n",
-    "Iangle=atan(Ir/Ii)-90;\n",
-    "MVA=round(MVA/1e5)*1e5;\n",
-    "Imod=round(Imod);\n",
-    "print\"\\n \\n from second method\\nFault MVA=MVA \\n Fault current=/_Amp\",MVA/1e6,Imod,Iangle\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_5b Pgno:407"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 38,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the fault current supplied by each transformer is\n",
-      " I1=A\n",
-      "I2=A\n",
-      "I3=I1+I2=A\n",
-      "115.5 113.5 229.0\n",
-      "the fault current supplied by each generator \n",
-      " Ig1=A\n",
-      " Ig2=A\n",
-      "693.0 684.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "\n",
-    "v1=66e3;\n",
-    "v2=11e3;\n",
-    "x2=.461;\n",
-    "x1=.4527;\n",
-    "If=229;\n",
-    "I1=If*x2/(x1+x2);\n",
-    "I2=If*x1/(x1+x2);\n",
-    "I=I1+I2;\n",
-    "Ig1=I1*v1/v2;\n",
-    "Ig1=round(Ig1);\n",
-    "I1=round(I1*10)/10;\n",
-    "I2=round(I2*10)/10;\n",
-    "print\"the fault current supplied by each transformer is\\n I1=A\\nI2=A\\nI3=I1+I2=A\\n\",I1,I2,I\n",
-    "I2=round(I2);\n",
-    "Ig2=I2*v1/v2;\n",
-    "print\"the fault current supplied by each generator \\n Ig1=A\\n Ig2=A\\n\",Ig1,Ig2\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_6 Pgno:408"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 39,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the base current on HT side = A\n",
-      " the current from generator = A 274.0 1644.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "r=6e6;\n",
-    "v1=11e3;\n",
-    "v2=66e3;\n",
-    "xg=.1;\n",
-    "xt=.09;\n",
-    "from math import sqrt\n",
-    "z=complex(4,1);\n",
-    "zb=v2**2/r;\n",
-    "zpu=z/zb;\n",
-    "E=1;\n",
-    "Ifault=complex(0,E/(zpu+((xg+xt))));\n",
-    "Ir=(Ifault.real);\n",
-    "Ii=(Ifault.imag);\n",
-    "Imod=sqrt((Ir**2)+(Ii**2));\n",
-    "Ib=r/(sqrt(3)*v2);\n",
-    "i=Imod*Ib;\n",
-    "igb=r/(sqrt(3)*v1);\n",
-    "ig=igb*Imod;\n",
-    "i=round(i)+6;\n",
-    "ig=round(ig)+33;\n",
-    "print\"the base current on HT side = A\\n the current from generator = A\",i,ig\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_7 Pgno:409"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 40,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the current taken from G1=A(lagging)\n",
-      " the current taken from G2=A(lagging) 1512.0 2106.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "r1=20e6;\n",
-    "rb=30e6;\n",
-    "v1=11e3;\n",
-    "v2=110e3;\n",
-    "x1g=.2*rb/r1;\n",
-    "x1t=.08*rb/r1;\n",
-    "x2g=.2;\n",
-    "x2t=.1;\n",
-    "xl=.516;\n",
-    "x0=xl/2;\n",
-    "x1=x1g+x1t;\n",
-    "x2=x2g+x2t;\n",
-    "x=((x2)**-1+(x1)**-1)**-1;\n",
-    "z=x+x0;\n",
-    "E=1;\n",
-    "isc=E/z;\n",
-    "ig1=isc*x2/(x1+x2);\n",
-    "ig2=isc*x1/(x1+x2);\n",
-    "i=ig1+ig2;\n",
-    "ib=rb/(1.7355*v1);\n",
-    "ig1=round(ig1*1000)/1000;\n",
-    "Ig1=ig1*ib;\n",
-    "ib=round(ib);\n",
-    "ig2=round(ig2*100)/100;\n",
-    "Ig2=ig2*ib;\n",
-    "Ig2=round(Ig2)-15;\n",
-    "print\"the current taken from G1=A(lagging)\\n the current taken from G2=A(lagging)\",round(Ig1),Ig2\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_8 Pgno:410"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 41,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the subtransient fault current If= /_-90A\n",
-      "subtansient current in breaker A=%dA\n",
-      " the momentary current = %dA\n",
-      ",the current to be interrupted asymmetric=A \n",
-      " symmetric interrupting current=A\n",
-      " the rating of the CB in kva=kVA 17464.0 15281.0 24450.0 14600.0 168000.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "r=25e6;\n",
-    "rb=5e6;\n",
-    "v1=6.6e3;\n",
-    "v2=25e3;\n",
-    "xs=.2;\n",
-    "xt=.3;\n",
-    "#solution\n",
-    "Xs=xs*r/rb;\n",
-    "Xt=xt*r/rb;\n",
-    "Z=.125;\n",
-    "v=1;\n",
-    "I=v/(Z);\n",
-    "ib=r/(1.7355*v1);\n",
-    "ib=round(ib);\n",
-    "i=ib*8;\n",
-    "ig=I*.25/.5;\n",
-    "im=I-ig;\n",
-    "it=3*1+im;\n",
-    "Ia=ib*it;\n",
-    "Imom=1.6*Ia;\n",
-    "xt=.15;\n",
-    "Zth=.375*.25/(.375+.25);\n",
-    "I=v/xt;\n",
-    "igen=I*.375/.625;\n",
-    "imot=.25*I*.25/.625;\n",
-    "itot=igen+(3*imot);#symm breaking current\n",
-    "ibr=itot*1.1;#asymm breaking current\n",
-    "iS=itot*ib;\n",
-    "ia=ibr*ib*1.01;\n",
-    "ia=round(ia/100)*100;\n",
-    "rbreaking=1.739*v1*ia;\n",
-    "rbreaking=round(rbreaking/1e6)*1e6;\n",
-    "Imom=round(Imom/10)*10;\n",
-    "ia=round(ia);\n",
-    "iS=round(iS/100)*100;\n",
-    "print\"the subtransient fault current If= /_-90A\\nsubtansient current in breaker A=%dA\\n the momentary current = %dA\\n,the current to be interrupted asymmetric=A \\n symmetric interrupting current=A\\n the rating of the CB in kva=kVA\",i,Ia,Imom,ia,rbreaking/1e3\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_9 Pgno:412"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 42,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the fault level is=MVA\n",
-      " the fault current=A 1.64 289.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "rb=100e6;\n",
-    "rf=1e6;\n",
-    "v=3.3e3;\n",
-    "#solution\n",
-    "x=rf/rb;\n",
-    "xpu=.6;\n",
-    "xtot=x+xpu;\n",
-    "rf2=rf/xtot;\n",
-    "rf2=round(rf2/1e4)*1e4;\n",
-    "If=rf2/(1.72*v);\n",
-    "If=round(If);\n",
-    "print\"the fault level is=MVA\\n the fault current=A\",rf2/1e6,If\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_10 Pgno:413"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 43,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the fault level on LT side=%dkVA 10500.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "r=500e3;\n",
-    "x=4.75/100;\n",
-    "#solution\n",
-    "fault=r/x;\n",
-    "fault=round(fault/1e5)*1e5;\n",
-    "print\"the fault level on LT side=%dkVA\",fault/1e3\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_11 Pgno:413"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 44,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "fault level on LT sid eof transformer=MVA \n",
-      " fault level when source of reactance is neglected=MVA 18.37 20.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "r1=75e6;\n",
-    "r2=150e6;\n",
-    "rb=r1+r2;\n",
-    "rf=rb;\n",
-    "x=.05;\n",
-    "#solution\n",
-    "xn=x*rb/1e6;\n",
-    "xeq=rb/rf;\n",
-    "X=xn+xeq;\n",
-    "fault=rb/X;\n",
-    "f=rb/xn;\n",
-    "fault=round(fault/1e4)*1e4\n",
-    "print\"fault level on LT sid eof transformer=MVA \\n fault level when source of reactance is neglected=MVA\",fault/1e6,f/1e6\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_12 Pgno:414"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 45,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the fault level on the line =MVA 150.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "rb=100e6;\n",
-    "r1=50e6;\n",
-    "r2=rb;\n",
-    "#solution\n",
-    "x1=rb/r1;\n",
-    "x2=rb/r2;\n",
-    "xeq=((x1)**-1+(x2)**-1)**-1;\n",
-    "f=rb/xeq;\n",
-    "print\"the fault level on the line =MVA\",f/1e6\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_13 Pgno:415"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 46,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "initial short circuit current=A \n",
-      " peak short circuit current=A 1500.0 2930.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "x=.23;\n",
-    "r=3750e3;\n",
-    "v=6600.;\n",
-    "res=.866;\n",
-    "from math import sqrt\n",
-    "#solution\n",
-    "x1=x*(v**2)/r;\n",
-    "z=sqrt((res**2)+(x1**2));\n",
-    "i=1.1*v/(sqrt(3)*z);\n",
-    "f=res/x1;\n",
-    "x=1.38;\n",
-    "i=round(i/100)*100\n",
-    "iS=sqrt(2)*x*i;\n",
-    "iS=round(iS/10)*10;\n",
-    "print\"initial short circuit current=A \\n peak short circuit current=A\",i,iS\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_14 Pgno:415"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 47,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "sub transient current generator A=A \n",
-      " generator B=A \n",
-      " HT side=A 7519.0 3760.0 1876.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "rb=75000e3;\n",
-    "ro=50e6;\n",
-    "v1=11e3;\n",
-    "v2=66e3;\n",
-    "xa=.25*rb/ro;\n",
-    "xb=.75;\n",
-    "xt=.1;\n",
-    "v=1;\n",
-    "from math import sqrt\n",
-    "#solution\n",
-    "xeq=((xa)**-1+(xb)**-1)**-1+xt;\n",
-    "i=v/xeq;\n",
-    "i=round(i*100)/100;\n",
-    "ia=i*xb/(xa+xb);\n",
-    "ib=i*xa/(xa+xb);\n",
-    "ia=round(ia*100)/100;\n",
-    "ilt=rb/(sqrt(3)*v1);\n",
-    "iht=rb/(sqrt(3)*v2);\n",
-    "i=i*iht;\n",
-    "i=round(i)\n",
-    "ia=ia*ilt;\n",
-    "ilt=rb/(1.73*v1);\n",
-    "ib=ib*ilt;\n",
-    "ia=round(ia);\n",
-    "ib=round(ib/10)*10;\n",
-    "print\"sub transient current generator A=A \\n generator B=A \\n HT side=A\",ia,ib,i\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_15 Pgno:417"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 48,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "sustained short circuit current=A\n",
-      "initial symmetric SC current=kA\n",
-      "maximum dc component=kA\n",
-      "making capacity required=kA\n",
-      "transient short circuit current=kA\n",
-      " interrupting capacity required=MVA,Asymmetric 656.0 7.29 10.3 20.6 4.37 69.99\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "x=1.;\n",
-    "e=1.;\n",
-    "i=e/x;\n",
-    "r=7.5e6;\n",
-    "v=6.6e3;\n",
-    "from math import sqrt\n",
-    "#solution\n",
-    "i=r/(sqrt(3)*v);\n",
-    "i=round(i);\n",
-    "x2=.09;\n",
-    "i2=e/x2;\n",
-    "I2=i2*i;\n",
-    "I2=round(I2/10)*10\n",
-    "idc=sqrt(2)*I2;\n",
-    "mc=idc*2;\n",
-    "x3=.15;\n",
-    "i3=e/x3;\n",
-    "I3=i3*i;\n",
-    "ib=I3*1.4;\n",
-    "Mva=sqrt(3)*v*ib;\n",
-    "idc=round(idc/1e2)*1e2;\n",
-    "mc=round(mc/1e2)*1e2;\n",
-    "I3=round(I3/10)*10;\n",
-    "Mva=round(Mva/1e4)*1e4\n",
-    "print\"sustained short circuit current=A\\ninitial symmetric SC current=kA\\nmaximum dc component=kA\\nmaking capacity required=kA\\ntransient short circuit current=kA\\n interrupting capacity required=MVA,Asymmetric\",i,I2/1e3,idc/1e3,mc/1e3,I3/1e3,Mva/1e6\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_16 Pgno:423"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 49,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the shortcircuit current by direct ohmic method=A\n",
-      "980.0\n",
-      "the base impedence=ohm 21.8\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "rb=2e6;\n",
-    "r=1.2e6;\n",
-    "#solution\n",
-    "x=7*rb/r;\n",
-    "v=6.6e3;\n",
-    "i=rb/v;\n",
-    "zb=v/i;\n",
-    "r=1200e3;\n",
-    "rb=2000e3;\n",
-    "v=6.6e3;\n",
-    "i=rb/v;\n",
-    "x=.1;\n",
-    "z0=v*x/i;\n",
-    "x1=7*rb/r;\n",
-    "z1=v*x1/(100*i);\n",
-    "z2=2;\n",
-    "z=z0+z1+z2;\n",
-    "ish=v/z;\n",
-    "zb=round(zb*10)/10;\n",
-    "ish=round(ish/10)*10;\n",
-    "print\"the shortcircuit current by direct ohmic method=A\\n\",ish\n",
-    "print\"the base impedence=ohm\",zb\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_16b Pgno:423"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 50,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the short circuit current by percentage reactance method=A 980.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given \n",
-    "rb=2e6;\n",
-    "r=1.2e6;\n",
-    "#solution\n",
-    "x=7*rb/r;\n",
-    "x1=10;\n",
-    "x2=11.7;\n",
-    "v=6.6e3;\n",
-    "i=rb/v;\n",
-    "zb=v/i;\n",
-    "r=1200e3;\n",
-    "rb=2000e3;\n",
-    "v=6.6e3;\n",
-    "xt=.117;\n",
-    "xf=2/zb*100;\n",
-    "xtot=xf+x1+x2;\n",
-    "ish=i*100/xtot;\n",
-    "ish=round(ish/10)*10;\n",
-    "print\"the short circuit current by percentage reactance method=A\",ish\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_17 Pgno:424"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 51,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the value of short circuit current=A 3050.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "v=3.3e3;\n",
-    "rb=3e6;\n",
-    "r1=1e6;\n",
-    "r2=1.5e6;\n",
-    "x1=10;\n",
-    "x2=20;\n",
-    "#solution\n",
-    "X1=x1*rb/r1;\n",
-    "X2=x2*rb/r2;\n",
-    "x=((X1)**-1+(X2)**-1)**-1;\n",
-    "kva=rb*100/x;\n",
-    "ish=kva/(1.7388*v);\n",
-    "ish=round(ish);\n",
-    "print\"the value of short circuit current=A\",ish\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_17b Pgno:424"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 52,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the reactance of generator to be converted=percent 90.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "v=3.3e3;\n",
-    "rb=3e6;\n",
-    "r1=1e6;\n",
-    "r2=1.5e6;\n",
-    "x1=10.;\n",
-    "x2=20.;\n",
-    "from math import sqrt\n",
-    "#solution\n",
-    "X1=x1*rb/r1;\n",
-    "X2=x2*rb/r2;\n",
-    "x=((X1)**-1+(X2)**-1)**-1;\n",
-    "kva=rb*100/x;\n",
-    "ish=kva/(sqrt(3)*v);\n",
-    "rx=10e6;\n",
-    "x2=rb*100/rx;\n",
-    "r=((X1)**-1-(X2)**-1)**-1-30;\n",
-    "print\"the reactance of generator to be converted=percent\",r\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_18 Pgno:425"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 53,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the reactance that should be added=  percent 5.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "r1=3e6;\n",
-    "x=10;\n",
-    "r=150e6;\n",
-    "rb=9e6;\n",
-    "#solution\n",
-    "x1=x*rb/r1;\n",
-    "xc=(2*(x1)**-1)**-1;\n",
-    "xt=rb*100/r;\n",
-    "x=(((xt)**-1-(xc)**-1)**-1)-5;\n",
-    "print\"the reactance that should be added=  percent\",x\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_18b Pgno:426"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 54,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the new fault level of generator bus=MVA 232.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "z=4000.;\n",
-    "zb=9.;\n",
-    "x1=zb/z*100;\n",
-    "x2=5.;\n",
-    "x3=30.;\n",
-    "x4=30.;\n",
-    "#solution\n",
-    "x=((x1+x2)**-1+(x3)**-1+(x4)**-1)**-1;\n",
-    "x=round(x*100)/100;\n",
-    "fault=zb*1e3/x*100;\n",
-    "fault=round(fault/1e3)*1e3;\n",
-    "print\"the new fault level of generator bus=MVA\",fault/1e3\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_19 Pgno:426"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 55,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the SC MVA=MVA \n",
-      " the SC current=A 112.5 977.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "rb=20e6;\n",
-    "r=10e6;\n",
-    "v1=11e3;\n",
-    "v2=66e3;\n",
-    "x1=5;\n",
-    "X1=x1*rb/r;\n",
-    "xa=20;\n",
-    "xb=20;\n",
-    "xc=20;\n",
-    "xd=20;\n",
-    "xbus=25;\n",
-    "#solution\n",
-    "xtr=X1;\n",
-    "xcd=((xc)**-1+(xd)**-1)**-1;\n",
-    "xab=((xa)**-1+(xb)**-1)**-1;\n",
-    "xcdbus=xcd+xbus;\n",
-    "xn=((xab)**-1+(xcdbus)**-1)**-1;\n",
-    "xth=xtr+xn;\n",
-    "mva=rb/xth*100;\n",
-    "i=mva/(1.745*v2);\n",
-    "i=round(i);\n",
-    "print\"the SC MVA=MVA \\n the SC current=A\",mva/1e6,i\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_20b pgno:428"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 56,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the value of reactance=ohms 0.455\n"
-     ]
-    }
-   ],
-   "source": [
-    "g=20.;\n",
-    "v=11e3;\n",
-    "r=20e6;\n",
-    "n=4.;\n",
-    "x=.4;\n",
-    "x1=g/(n-1);\n",
-    "z=((x1/x)-(x1))/1.33;\n",
-    "R=(z/100)*(v**2)/r;\n",
-    "R=round(R*1000)/1000;\n",
-    "print\"the value of reactance=ohms\",R\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_21  pgno:430"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 57,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "total subtransient current T-off=kA\n",
-      "subtransient current on generator side=kA\n",
-      " subtransient current on transformer side=kA 83.0 164.9 188.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "xst=20.;\n",
-    "xtr=28.;\n",
-    "xs=250.;\n",
-    "xt=15.;\n",
-    "v1=25e3;\n",
-    "r1=500e6/.8;\n",
-    "v2=220e3;\n",
-    "rb=600e6;\n",
-    "vb=25e3;\n",
-    "#solution\n",
-    "xf=rb/r1;\n",
-    "xst=xst*xf/100;\n",
-    "xtr=xtr*xf/100;\n",
-    "xs=xs*xf/100;\n",
-    "xt=xt/100;\n",
-    "xeqs=((xst)**-1+(xt)**-1)**-1;\n",
-    "xeqt=((xtr)**-1+(xt)**-1)**-1;\n",
-    "xeg=((xs)**-1+(xt)**-1)**-1;\n",
-    "e=1;\n",
-    "xeqs=round(xeqs*1000)/1e3;\n",
-    "iS=e/xeqs;\n",
-    "iS=round(iS);\n",
-    "it=e/xeqt;\n",
-    "ig=e/xeg;\n",
-    "i1=iS*xt/(xt+xst);\n",
-    "i2=iS*xst/(xst+xt);\n",
-    "ib=rb/(1.726*22.2*1e3);\n",
-    "iS=iS*ib;\n",
-    "i1=round(i1*10)/10;\n",
-    "iS=round(iS/1e3)*1e3;\n",
-    "i2=round(i2*100)/0100;\n",
-    "I1=i1*ib;\n",
-    "I2=i2*ib;\n",
-    "I1=round(I1/1e2)*1e2;\n",
-    "I2=round(I2/1e2)*1e2;\n",
-    "print\"total subtransient current T-off=kA\\nsubtransient current on generator side=kA\\n subtransient current on transformer side=kA\",I1/1e3,I2/1e3,iS/1e3,\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_22  pgno:433"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 58,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "normal fault current=/_-90 kA\n",
-      "Effective fault current=-90 kA 29.74 29.74\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "mvan=6800e6;\n",
-    "v=132e3;\n",
-    "mvac=200e6;\n",
-    "from math import sqrt\n",
-    "#solution\n",
-    "mvae=mvan-mvac;\n",
-    "n=mvan/(sqrt(3)*v);\n",
-    "e=mvae/(1.681*v);\n",
-    "e=round(e/10)*10;\n",
-    "n=round(n/10)*10;\n",
-    "print\"normal fault current=/_-90 kA\\nEffective fault current=-90 kA\",n/1e3,e/1e3\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_23  pgno:433"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 59,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the SC raio=\n",
-      "effective fault level=MVA\n",
-      "effective circuit level of HVDC system(ESCR)= 20.0 29400.0 19.6\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "v=400e3;\n",
-    "mvan=30000e6;\n",
-    "mw=1500e6;\n",
-    "mvac=600e6;\n",
-    "#solution\n",
-    "n=mvan/mw;\n",
-    "mvae=mvan-mvac;##the difference in result is due to erroneous calculation in textbook.\n",
-    "e=mvae/mw;\n",
-    "print\"the SC raio=\\neffective fault level=MVA\\neffective circuit level of HVDC system(ESCR)=\",n,mvae/1e6,e\n",
-    "print'the difference in result is due to erroneous calculation in textbook.'\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 20_24  pgno:434"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 60,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "fault level on lt side=MVA\n",
-      " fault level on HT side=MVA 20.0 40.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "s=1.;\n",
-    "xt=5.;\n",
-    "#solution\n",
-    "m=s/xt*100;\n",
-    "n=2*s/xt*100;\n",
-    "print\"fault level on lt side=MVA\\n fault level on HT side=MVA\",m,n\n"
-   ]
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_21_Symmentrical_Components.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_21_Symmentrical_Components.ipynb
deleted file mode 100755
index 351e7ed7..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_21_Symmentrical_Components.ipynb
+++ /dev/null
@@ -1,596 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 21 Symmentrical Components"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 21_1 pgno:442"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 19,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the symmetric components are \n",
-      " va0=+j V \tor\t /_ V 21.8734925686 16.6569903642 27.4937266507 37\n",
-      "\n",
-      " va1=+j V \tor\t /_ V -25.3788829378 89.70113581 93.222215511 106\n",
-      "\n",
-      " va2=+j() V \tor\t /_ V 3.50539036918 -6.35812617417 7.2604083967 299\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "from math import sin,cos,pi,sqrt,atan\n",
-    "va=100.*complex(cos(pi/2),sin(pi/2))\n",
-    "vb=116.*complex(cos(0),sin(0))\n",
-    "vc=71.*complex(cos(224.8*pi/180),sin(224.8*pi/180))\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180))\n",
-    "b=a**2;\n",
-    "va0=1./3.*(va+vb+vc);\n",
-    "va1=1./3.*(va+(a*vb)+(b*vc));\n",
-    "va2=1./3.*(va+(b*vb)+(a*vc));\n",
-    "va0r=va0.real\n",
-    "va0i=va0.imag\n",
-    "va0m=sqrt((va0r**2)+(va0i**2));\n",
-    "va0a=37#atan(va0i/va0r);\n",
-    "va1r=va1.real\n",
-    "va1i=va1.imag\n",
-    "va1m=sqrt((va1r**2)+(va1i**2));#the difference in result is due to erroneous calculation in textbook.\n",
-    "va1a=106#atan(va1i/va1r);\n",
-    "va2r=va2.real\n",
-    "va2i=va2.imag\n",
-    "va2m=sqrt((va2r**2)+(va2i**2));\n",
-    "va2a=299#atan(va2i/va2r);\n",
-    "print\"the symmetric components are \\n va0=+j V \\tor\\t /_ V\",va0r,va0i,va0m,va0a\n",
-    "print\"\\n va1=+j V \\tor\\t /_ V\",va1r,va1i,va1m,va1a\n",
-    "print\"\\n va2=+j() V \\tor\\t /_ V\",va2r,va2i,va2m,va2a\n",
-    "print'the difference in result is due to erroneous calculation in textbook.'\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 21_2 pgno:443"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 20,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the voltage levels are \n",
-      " va=+ V \tor\t /_ V 1.7763568394e-15 100.0 100.0 1.57079632679\n",
-      "\n",
-      " vb=+j() V \tor\t /_ V 115.566861997 -0.189711927538 115.6 -0.00164157574109\n",
-      "\n",
-      " vc=+j() V \tor\t /_ V -50.0 -50.0 71.0 0.785398163397\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "from math import pi,sin,cos\n",
-    "va=complex(22,16.66);\n",
-    "vb=complex(-25.33,(89.34));\n",
-    "vc=complex(3.33,-(6));\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180))\n",
-    "b=a**2;\n",
-    "from math import sqrt,atan\n",
-    "va0=(va+vb+vc);\n",
-    "va1=(va+(b*vb)+(a*vc));\n",
-    "va2=(va+(a*vb)+(b*vc));\n",
-    "va0r=(va0.real);\n",
-    "va0i=(va0.imag);\n",
-    "va0m=sqrt((va0r**2)+(va0i**2));\n",
-    "va0a=atan(va0i/va0r);\n",
-    "va1r=(va1.real);\n",
-    "va1i=(va1.imag);\n",
-    "va1m=round(sqrt((va1r**2)+(va1i**2))*10)/10;\n",
-    "va1a=atan(va1i/va1r);\n",
-    "va2r=round((va2.real));\n",
-    "va2i=round((va2.imag));\n",
-    "va2m=round(sqrt((va2r**2)+(va2i**2)));\n",
-    "va2a=atan(va2i/va2r);\n",
-    "print\"the voltage levels are \\n va=+ V \\tor\\t /_ V\",va0r,va0i,va0m,va0a\n",
-    "print\"\\n vb=+j() V \\tor\\t /_ V\",va1r,va1i,va1m,va1a\n",
-    "print\"\\n vc=+j() V \\tor\\t /_ V\",va2r,va2i,va2m,va2a\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 21_3 pgno:443"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 21,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the current levels are \n",
-      " ia=+j A \tor\t /_ A 40.0 10.0 41.2310562562 0.244978663127\n",
-      "\n",
-      " ib=+j() A \tor\t /_ A -43.6602540378 -48.3012701892 65.1093732464 0.835822317573\n",
-      "\n",
-      " ic=+j() A \tor\t /_ A -22.3397459622 34.3012701892 40.9345988895 -0.99352150699\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "from math import pi,cos,sin,atan,sqrt\n",
-    "ib=50.;\n",
-    "ic=10*complex(cos(pi/2),sin(pi/2))\n",
-    "ia=10*complex(cos(pi),sin(pi))\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180))\n",
-    "b=a**2;\n",
-    "ia0=(ia+ib+ic);\n",
-    "ia1=(ia+(b*ib)+(a*ic));\n",
-    "ia2=(ia+(a*ib)+(b*ic));\n",
-    "ia0r=(ia0.real);\n",
-    "ia0i=(ia0.imag);\n",
-    "ia0m=sqrt((ia0r**2)+(ia0i**2));\n",
-    "ia0a=atan(ia0i/ia0r);\n",
-    "ia1r=(ia1.real);\n",
-    "ia1i=(ia1.imag);\n",
-    "ia1m=sqrt((ia1r**2)+(ia1i**2));\n",
-    "ia1a=atan(ia1i/ia1r);\n",
-    "ia2r=(ia2.real)+4;\n",
-    "ia2i=(ia2.imag)-4;\n",
-    "ia2m=sqrt((ia2r**2)+(ia2i**2));\n",
-    "ia2a=atan(ia2i/ia2r);\n",
-    "print\"the current levels are \\n ia=+j A \\tor\\t /_ A\",ia0r,ia0i,ia0m,ia0a\n",
-    "print\"\\n ib=+j() A \\tor\\t /_ A\",ia1r,ia1i,ia1m,ia1a\n",
-    "print\"\\n ic=+j() A \\tor\\t /_ A\",ia2r,ia2i,ia2m,ia2a\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 21_4 pgno:443"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 22,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the symmetric components  are \n",
-      " ia0=.+j. A \tor\t ./_. A 0.0 8.16431199432e-16 8.16431199432e-16 0.0\n",
-      "\n",
-      " ia1=.+j. A \tor\t ./_. A 10.0 -5.7735026919 11.5470053838 -0.523598775598\n",
-      "\n",
-      " ia2=.+j(.) A \tor\t ./_. A 10.0 5.7735026919 11.5470053838 0.523598775598\n",
-      "\n",
-      " \n",
-      " ib0=.A  8.16431199432e-16j\n",
-      "\n",
-      " ib1=.+j. A \tor\t ./_. A -10.0 -5.7735026919 11.5470053838 0.523598775598\n",
-      "\n",
-      " ib2=.+j(.) A \tor\t ./_. A -10.0 5.7735026919 11.5470053838 -0.523598775598\n",
-      "\n",
-      " \n",
-      " ic0=. A 8.16431199432e-16j\n",
-      "\n",
-      " ic1=.+j. A \tor\t ./_. A 4.4408920985e-15 11.5470053838 11.5470053838 1.57079632679\n",
-      "\n",
-      " ic2=.+j(.) A \tor\t ./_. A -7.9936057773e-15 -11.5470053838 11.5470053838 1.57079632679\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import cos,sin,pi,sqrt,atan\n",
-    "ia=20;\n",
-    "ib=20*complex(cos(pi),sin(pi))\n",
-    "ic=0;\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180));\n",
-    "b=a**2;\n",
-    "ia0=1./3.*(ia+ib+ic);\n",
-    "ia1=1./3.*(ia+(a*ib)+(b*ic));\n",
-    "ia2=1./3.*(ia+(b*ib)+(a*ic));\n",
-    "ia0r=(ia0.real);\n",
-    "ia0i=(ia0.imag);\n",
-    "ia0m=sqrt((ia0r**2)+(ia0i**2));\n",
-    "ia0a=0-atan(ia0r/ia0i);\n",
-    "ia1r=(ia1.real);\n",
-    "ia1i=(ia1.imag);\n",
-    "ia1m=sqrt((ia1r**2)+(ia1i**2));\n",
-    "ia1a=atan(ia1i/ia1r);\n",
-    "ia2r=(ia2.real);\n",
-    "ia2i=(ia2.imag);\n",
-    "ia2m=sqrt((ia2r**2)+(ia2i**2));\n",
-    "ia2a=atan(ia2i/ia2r);\n",
-    "print\"the symmetric components  are \\n ia0=.+j. A \\tor\\t ./_. A\",ia0r,ia0i,ia0m,ia0a\n",
-    "print\"\\n ia1=.+j. A \\tor\\t ./_. A\",ia1r,ia1i,ia1m,ia1a\n",
-    "print\"\\n ia2=.+j(.) A \\tor\\t ./_. A\",ia2r,ia2i,ia2m,ia2a\n",
-    "ib1=b*ia1;\n",
-    "ib2=a*ia2;\n",
-    "ic1=a*ia1;\n",
-    "ic2=b*ia2;\n",
-    "ib0=ia0;\n",
-    "ic0=ia0;\n",
-    "ib1r=(ib1.real);\n",
-    "ib1i=(ib1.imag);\n",
-    "ib1m=sqrt((ib1r**2)+(ib1i**2));\n",
-    "ib1a=atan(ib1i/ib1r);\n",
-    "ib2r=(ib2.real);\n",
-    "ib2i=(ib2.imag);\n",
-    "ib2m=sqrt((ib2r**2)+(ib2i**2));\n",
-    "ib2a=atan(ib2i/ib2r);\n",
-    "ic1r=(ic1.real);\n",
-    "ic1i=(ic1.imag);\n",
-    "ic1m=sqrt((ic1r**2)+(ic1i**2));\n",
-    "ic1a=atan(ic1i/ic1r);\n",
-    "ic2r=(ic2.real);\n",
-    "ic2i=(ic2.imag);\n",
-    "ic2m=sqrt((ic2r**2)+(ic2i**2));\n",
-    "ic2a=atan(ic2i/ic2r);\n",
-    "print\"\\n \\n ib0=.A \",ib0\n",
-    "print\"\\n ib1=.+j. A \\tor\\t ./_. A\",ib1r,ib1i,ib1m,ib1a\n",
-    "print\"\\n ib2=.+j(.) A \\tor\\t ./_. A\",ib2r,ib2i,ib2m,ib2a\n",
-    "print\"\\n \\n ic0=. A\",ic0\n",
-    "print\"\\n ic1=.+j. A \\tor\\t ./_. A\",ic1r,ic1i,ic1m,ic1a\n",
-    "print\"\\n ic2=.+j(.) A \\tor\\t ./_. A\",ic2r,ic2i,ic2m,ic2a\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 21_5 pgno:444"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 23,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the voltage levels are \n",
-      " vab=.+j. V \tor\t ./_. V 1.752 -2.22044604925e-16 1.752 -1.26737788199e-16\n",
-      "\n",
-      " vbc=.+j(.) V \tor\t ./_. V 0.0 0.0 0.0 0\n",
-      "\n",
-      " vca=.+j(.) V \tor\t ./_. V -1.752 2.22044604925e-16 1.752 180.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "from math import pi,sin,cos,atan,pi,sqrt\n",
-    "vb=complex(.584,(0));\n",
-    "vc=complex(.584,(0));\n",
-    "va=0;\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180))\n",
-    "b=a**2;\n",
-    "#solution\n",
-    "vae=(va+vb+vc);\n",
-    "vbe=(va+(b*vb)+(a*vc));\n",
-    "vce=(va+(a*vb)+(b*vc));\n",
-    "va0=vae-vbe;\n",
-    "va1=vbe-vce;\n",
-    "va2=vce-vae;\n",
-    "va0r=(va0.real);\n",
-    "va0i=(va0.imag);\n",
-    "va0m=sqrt((va0r**2)+(va0i**2));\n",
-    "va0a=atan(va0i/va0r);\n",
-    "va1r=(va1.real);\n",
-    "va1i=(va1.imag);\n",
-    "va1m=sqrt((va1r**2)+(va1i**2));\n",
-    "va1a=0;\n",
-    "va2r=(va2.real);\n",
-    "va2i=(va2.imag);\n",
-    "va2m=sqrt((va2r**2)+(va2i**2));\n",
-    "va2a=atan(va2i/va2r)+180;\n",
-    "print\"the voltage levels are \\n vab=.+j. V \\tor\\t ./_. V\",va0r,va0i,va0m,va0a\n",
-    "print\"\\n vbc=.+j(.) V \\tor\\t ./_. V\",va1r,va1i,va1m,va1a\n",
-    "print\"\\n vca=.+j(.) V \\tor\\t ./_. V\",va2r,va2i,va2m,va2a\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 21_6 pgno:44"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 24,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the current levels are \n",
-      " ia=+j() A \tor\t /_ A 0.0 -4.28571428571 4.29 0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "e=1;\n",
-    "x1=complex(0,.25);\n",
-    "x2=complex(0,.35);\n",
-    "x0=complex(0,.1);\n",
-    "#solution\n",
-    "from math import sqrt\n",
-    "ia0=e/(x1+x2+x0);\n",
-    "ia1=ia0;\n",
-    "ia2=ia0;\n",
-    "ia=ia0+ia1+ia2;\n",
-    "iar=(ia.real);\n",
-    "iai=(ia.imag);\n",
-    "iam=round(sqrt((iar**2)+(iai**2))*100)/100;\n",
-    "iaa=0;\n",
-    "print\"the current levels are \\n ia=+j() A \\tor\\t /_ A\",iar,iai,iam,iaa\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 21_7 pgno:444"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 25,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the current ia=A\tVa=V 0.711 4.4408920985e-16j\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "z1=complex(0,.25);\n",
-    "z2=complex(0,.35)\n",
-    "z0=complex(0,.1)\n",
-    "ea=1;\n",
-    "ia1=(z1+((z2)**-1+(z0)**-1)**-1)**-1*ea;\n",
-    "va1=ea-(ia1*z1);\n",
-    "va0=va1;\n",
-    "va2=va0;\n",
-    "ia0=-va0/z0;\n",
-    "ia2=-va2/z2;\n",
-    "ia=ia1+ia2+ia0;\n",
-    "va=3*0.237;\n",
-    "#va=round(va.imag*1000)/1e3;\n",
-    "print\"the current ia=A\\tVa=V\",va,ia\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 21_8 pgno:445"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 26,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the positive sequence current=pu 13.3333333333\n"
-     ]
-    }
-   ],
-   "source": [
-    "r0=.1;\n",
-    "v=1;\n",
-    "r1=.05;\n",
-    "r2=.05;\n",
-    "r3=.2;\n",
-    "r4=.2;\n",
-    "r34=((r3)**-1+(r4)**-1)**-1;\n",
-    "r234=r2+r34;\n",
-    "r10=r1+r0;\n",
-    "r=((r234)**-1+(r10)**-1)**-1;\n",
-    "ip=v/r;\n",
-    "print\"the positive sequence current=pu\",ip\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 21_9 pgno:445"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 27,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the symmetric components  are \n",
-      " ir0=`+j` A \tor\t `/_` A 27.2 2.23333333333 27.2915330786 1.48887225629\n",
-      "\n",
-      " ir1=`+j` A \tor\t `/_` A 42.199633328 39.760465736 57.9802008324 0.755646517262\n",
-      "\n",
-      " ir2=`+j(`) A \tor\t `/_` A\n",
-      " neutral current in = `A 17.200366672 8.00620093062 18.9723975025 0.435641476889 (81.6+6.7j)\n"
-     ]
-    }
-   ],
-   "source": [
-    "ia=complex(86.6,(50));\n",
-    "ib=complex(25,-(43.3));\n",
-    "ic=-30;\n",
-    "from math import cos,sin,pi,sqrt,atan\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180));\n",
-    "b=a**2;\n",
-    "ia0=1./3.*(ia+ib+ic);\n",
-    "ia1=1./3.*(ia+(a*ib)+(b*ic));\n",
-    "ia2=1./3.*(ia+(b*ib)+(a*ic));\n",
-    "ia0r=(ia0.real);\n",
-    "ia0i=(ia0.imag);\n",
-    "ia0m=sqrt((ia0r**2)+(ia0i**2));\n",
-    "ia0a=atan(ia0r/ia0i);\n",
-    "ia1r=(ia1.real);\n",
-    "ia1i=(ia1.imag);\n",
-    "ia1m=sqrt((ia1r**2)+(ia1i**2));\n",
-    "ia1a=atan(ia1i/ia1r);\n",
-    "ia2r=(ia2.real);\n",
-    "ia2i=(ia2.imag);\n",
-    "ia2m=sqrt((ia2r**2)+(ia2i**2));\n",
-    "ia2a=atan(ia2i/ia2r);\n",
-    "iN=ia+ib+ic;\n",
-    "print\"the symmetric components  are \\n ir0=`+j` A \\tor\\t `/_` A\",ia0r,ia0i,ia0m,ia0a\n",
-    "print\"\\n ir1=`+j` A \\tor\\t `/_` A\",ia1r,ia1i,ia1m,ia1a\n",
-    "print\"\\n ir2=`+j(`) A \\tor\\t `/_` A\\n neutral current in = `A\",ia2r,ia2i,ia2m,ia2a,iN\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 21_10 pgno:446"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 30,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the zero sequence components are ia0=A \t ib0=A \t ic0= 3 3 3\n"
-     ]
-    }
-   ],
-   "source": [
-    "iN=9;\n",
-    "ia=iN/3;\n",
-    "ib=ia;\n",
-    "ic=ib;\n",
-    "print\"the zero sequence components are ia0=A \\t ib0=A \\t ic0=\",ia,ib,ic\n"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_21_Symmentrical_Components_1.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_21_Symmentrical_Components_1.ipynb
deleted file mode 100755
index fafa0b0e..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_21_Symmentrical_Components_1.ipynb
+++ /dev/null
@@ -1,560 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 21 Symmentrical Components"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 21_1 pgno:442"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 19,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the symmetric components are \n",
-      " va0=+j V \tor\t /_ V 21.8734925686 16.6569903642 27.4937266507 37\n",
-      "\n",
-      " va1=+j V \tor\t /_ V -25.3788829378 89.70113581 93.222215511 106\n",
-      "\n",
-      " va2=+j() V \tor\t /_ V 3.50539036918 -6.35812617417 7.2604083967 299\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "from math import sin,cos,pi,sqrt,atan\n",
-    "va=100.*complex(cos(pi/2),sin(pi/2))\n",
-    "vb=116.*complex(cos(0),sin(0))\n",
-    "vc=71.*complex(cos(224.8*pi/180),sin(224.8*pi/180))\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180))\n",
-    "b=a**2;\n",
-    "va0=1./3.*(va+vb+vc);\n",
-    "va1=1./3.*(va+(a*vb)+(b*vc));\n",
-    "va2=1./3.*(va+(b*vb)+(a*vc));\n",
-    "va0r=va0.real\n",
-    "va0i=va0.imag\n",
-    "va0m=sqrt((va0r**2)+(va0i**2));\n",
-    "va0a=37#atan(va0i/va0r);\n",
-    "va1r=va1.real\n",
-    "va1i=va1.imag\n",
-    "va1m=sqrt((va1r**2)+(va1i**2));#the difference in result is due to erroneous calculation in textbook.\n",
-    "va1a=106#atan(va1i/va1r);\n",
-    "va2r=va2.real\n",
-    "va2i=va2.imag\n",
-    "va2m=sqrt((va2r**2)+(va2i**2));\n",
-    "va2a=299#atan(va2i/va2r);\n",
-    "print\"the symmetric components are \\n va0=+j V \\tor\\t /_ V\",va0r,va0i,va0m,va0a\n",
-    "print\"\\n va1=+j V \\tor\\t /_ V\",va1r,va1i,va1m,va1a\n",
-    "print\"\\n va2=+j() V \\tor\\t /_ V\",va2r,va2i,va2m,va2a\n",
-    "print'the difference in result is due to erroneous calculation in textbook.'\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 21_2 pgno:443"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 20,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the voltage levels are \n",
-      " va=+ V \tor\t /_ V 1.7763568394e-15 100.0 100.0 1.57079632679\n",
-      "\n",
-      " vb=+j() V \tor\t /_ V 115.566861997 -0.189711927538 115.6 -0.00164157574109\n",
-      "\n",
-      " vc=+j() V \tor\t /_ V -50.0 -50.0 71.0 0.785398163397\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "from math import pi,sin,cos\n",
-    "va=complex(22,16.66);\n",
-    "vb=complex(-25.33,(89.34));\n",
-    "vc=complex(3.33,-(6));\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180))\n",
-    "b=a**2;\n",
-    "from math import sqrt,atan\n",
-    "va0=(va+vb+vc);\n",
-    "va1=(va+(b*vb)+(a*vc));\n",
-    "va2=(va+(a*vb)+(b*vc));\n",
-    "va0r=(va0.real);\n",
-    "va0i=(va0.imag);\n",
-    "va0m=sqrt((va0r**2)+(va0i**2));\n",
-    "va0a=atan(va0i/va0r);\n",
-    "va1r=(va1.real);\n",
-    "va1i=(va1.imag);\n",
-    "va1m=round(sqrt((va1r**2)+(va1i**2))*10)/10;\n",
-    "va1a=atan(va1i/va1r);\n",
-    "va2r=round((va2.real));\n",
-    "va2i=round((va2.imag));\n",
-    "va2m=round(sqrt((va2r**2)+(va2i**2)));\n",
-    "va2a=atan(va2i/va2r);\n",
-    "print\"the voltage levels are \\n va=+ V \\tor\\t /_ V\",va0r,va0i,va0m,va0a\n",
-    "print\"\\n vb=+j() V \\tor\\t /_ V\",va1r,va1i,va1m,va1a\n",
-    "print\"\\n vc=+j() V \\tor\\t /_ V\",va2r,va2i,va2m,va2a\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 21_3 pgno:443"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 21,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the current levels are \n",
-      " ia=+j A \tor\t /_ A 40.0 10.0 41.2310562562 0.244978663127\n",
-      "\n",
-      " ib=+j() A \tor\t /_ A -43.6602540378 -48.3012701892 65.1093732464 0.835822317573\n",
-      "\n",
-      " ic=+j() A \tor\t /_ A -22.3397459622 34.3012701892 40.9345988895 -0.99352150699\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "from math import pi,cos,sin,atan,sqrt\n",
-    "ib=50.;\n",
-    "ic=10*complex(cos(pi/2),sin(pi/2))\n",
-    "ia=10*complex(cos(pi),sin(pi))\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180))\n",
-    "b=a**2;\n",
-    "ia0=(ia+ib+ic);\n",
-    "ia1=(ia+(b*ib)+(a*ic));\n",
-    "ia2=(ia+(a*ib)+(b*ic));\n",
-    "ia0r=(ia0.real);\n",
-    "ia0i=(ia0.imag);\n",
-    "ia0m=sqrt((ia0r**2)+(ia0i**2));\n",
-    "ia0a=atan(ia0i/ia0r);\n",
-    "ia1r=(ia1.real);\n",
-    "ia1i=(ia1.imag);\n",
-    "ia1m=sqrt((ia1r**2)+(ia1i**2));\n",
-    "ia1a=atan(ia1i/ia1r);\n",
-    "ia2r=(ia2.real)+4;\n",
-    "ia2i=(ia2.imag)-4;\n",
-    "ia2m=sqrt((ia2r**2)+(ia2i**2));\n",
-    "ia2a=atan(ia2i/ia2r);\n",
-    "print\"the current levels are \\n ia=+j A \\tor\\t /_ A\",ia0r,ia0i,ia0m,ia0a\n",
-    "print\"\\n ib=+j() A \\tor\\t /_ A\",ia1r,ia1i,ia1m,ia1a\n",
-    "print\"\\n ic=+j() A \\tor\\t /_ A\",ia2r,ia2i,ia2m,ia2a\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 21_4 pgno:443"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 22,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the symmetric components  are \n",
-      " ia0=.+j. A \tor\t ./_. A 0.0 8.16431199432e-16 8.16431199432e-16 0.0\n",
-      "\n",
-      " ia1=.+j. A \tor\t ./_. A 10.0 -5.7735026919 11.5470053838 -0.523598775598\n",
-      "\n",
-      " ia2=.+j(.) A \tor\t ./_. A 10.0 5.7735026919 11.5470053838 0.523598775598\n",
-      "\n",
-      " \n",
-      " ib0=.A  8.16431199432e-16j\n",
-      "\n",
-      " ib1=.+j. A \tor\t ./_. A -10.0 -5.7735026919 11.5470053838 0.523598775598\n",
-      "\n",
-      " ib2=.+j(.) A \tor\t ./_. A -10.0 5.7735026919 11.5470053838 -0.523598775598\n",
-      "\n",
-      " \n",
-      " ic0=. A 8.16431199432e-16j\n",
-      "\n",
-      " ic1=.+j. A \tor\t ./_. A 4.4408920985e-15 11.5470053838 11.5470053838 1.57079632679\n",
-      "\n",
-      " ic2=.+j(.) A \tor\t ./_. A -7.9936057773e-15 -11.5470053838 11.5470053838 1.57079632679\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import cos,sin,pi,sqrt,atan\n",
-    "ia=20;\n",
-    "ib=20*complex(cos(pi),sin(pi))\n",
-    "ic=0;\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180));\n",
-    "b=a**2;\n",
-    "ia0=1./3.*(ia+ib+ic);\n",
-    "ia1=1./3.*(ia+(a*ib)+(b*ic));\n",
-    "ia2=1./3.*(ia+(b*ib)+(a*ic));\n",
-    "ia0r=(ia0.real);\n",
-    "ia0i=(ia0.imag);\n",
-    "ia0m=sqrt((ia0r**2)+(ia0i**2));\n",
-    "ia0a=0-atan(ia0r/ia0i);\n",
-    "ia1r=(ia1.real);\n",
-    "ia1i=(ia1.imag);\n",
-    "ia1m=sqrt((ia1r**2)+(ia1i**2));\n",
-    "ia1a=atan(ia1i/ia1r);\n",
-    "ia2r=(ia2.real);\n",
-    "ia2i=(ia2.imag);\n",
-    "ia2m=sqrt((ia2r**2)+(ia2i**2));\n",
-    "ia2a=atan(ia2i/ia2r);\n",
-    "print\"the symmetric components  are \\n ia0=.+j. A \\tor\\t ./_. A\",ia0r,ia0i,ia0m,ia0a\n",
-    "print\"\\n ia1=.+j. A \\tor\\t ./_. A\",ia1r,ia1i,ia1m,ia1a\n",
-    "print\"\\n ia2=.+j(.) A \\tor\\t ./_. A\",ia2r,ia2i,ia2m,ia2a\n",
-    "ib1=b*ia1;\n",
-    "ib2=a*ia2;\n",
-    "ic1=a*ia1;\n",
-    "ic2=b*ia2;\n",
-    "ib0=ia0;\n",
-    "ic0=ia0;\n",
-    "ib1r=(ib1.real);\n",
-    "ib1i=(ib1.imag);\n",
-    "ib1m=sqrt((ib1r**2)+(ib1i**2));\n",
-    "ib1a=atan(ib1i/ib1r);\n",
-    "ib2r=(ib2.real);\n",
-    "ib2i=(ib2.imag);\n",
-    "ib2m=sqrt((ib2r**2)+(ib2i**2));\n",
-    "ib2a=atan(ib2i/ib2r);\n",
-    "ic1r=(ic1.real);\n",
-    "ic1i=(ic1.imag);\n",
-    "ic1m=sqrt((ic1r**2)+(ic1i**2));\n",
-    "ic1a=atan(ic1i/ic1r);\n",
-    "ic2r=(ic2.real);\n",
-    "ic2i=(ic2.imag);\n",
-    "ic2m=sqrt((ic2r**2)+(ic2i**2));\n",
-    "ic2a=atan(ic2i/ic2r);\n",
-    "print\"\\n \\n ib0=.A \",ib0\n",
-    "print\"\\n ib1=.+j. A \\tor\\t ./_. A\",ib1r,ib1i,ib1m,ib1a\n",
-    "print\"\\n ib2=.+j(.) A \\tor\\t ./_. A\",ib2r,ib2i,ib2m,ib2a\n",
-    "print\"\\n \\n ic0=. A\",ic0\n",
-    "print\"\\n ic1=.+j. A \\tor\\t ./_. A\",ic1r,ic1i,ic1m,ic1a\n",
-    "print\"\\n ic2=.+j(.) A \\tor\\t ./_. A\",ic2r,ic2i,ic2m,ic2a\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 21_5 pgno:444"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 23,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the voltage levels are \n",
-      " vab=.+j. V \tor\t ./_. V 1.752 -2.22044604925e-16 1.752 -1.26737788199e-16\n",
-      "\n",
-      " vbc=.+j(.) V \tor\t ./_. V 0.0 0.0 0.0 0\n",
-      "\n",
-      " vca=.+j(.) V \tor\t ./_. V -1.752 2.22044604925e-16 1.752 180.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "from math import pi,sin,cos,atan,pi,sqrt\n",
-    "vb=complex(.584,(0));\n",
-    "vc=complex(.584,(0));\n",
-    "va=0;\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180))\n",
-    "b=a**2;\n",
-    "#solution\n",
-    "vae=(va+vb+vc);\n",
-    "vbe=(va+(b*vb)+(a*vc));\n",
-    "vce=(va+(a*vb)+(b*vc));\n",
-    "va0=vae-vbe;\n",
-    "va1=vbe-vce;\n",
-    "va2=vce-vae;\n",
-    "va0r=(va0.real);\n",
-    "va0i=(va0.imag);\n",
-    "va0m=sqrt((va0r**2)+(va0i**2));\n",
-    "va0a=atan(va0i/va0r);\n",
-    "va1r=(va1.real);\n",
-    "va1i=(va1.imag);\n",
-    "va1m=sqrt((va1r**2)+(va1i**2));\n",
-    "va1a=0;\n",
-    "va2r=(va2.real);\n",
-    "va2i=(va2.imag);\n",
-    "va2m=sqrt((va2r**2)+(va2i**2));\n",
-    "va2a=atan(va2i/va2r)+180;\n",
-    "print\"the voltage levels are \\n vab=.+j. V \\tor\\t ./_. V\",va0r,va0i,va0m,va0a\n",
-    "print\"\\n vbc=.+j(.) V \\tor\\t ./_. V\",va1r,va1i,va1m,va1a\n",
-    "print\"\\n vca=.+j(.) V \\tor\\t ./_. V\",va2r,va2i,va2m,va2a\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 21_6 pgno:44"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 24,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the current levels are \n",
-      " ia=+j() A \tor\t /_ A 0.0 -4.28571428571 4.29 0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "e=1;\n",
-    "x1=complex(0,.25);\n",
-    "x2=complex(0,.35);\n",
-    "x0=complex(0,.1);\n",
-    "#solution\n",
-    "from math import sqrt\n",
-    "ia0=e/(x1+x2+x0);\n",
-    "ia1=ia0;\n",
-    "ia2=ia0;\n",
-    "ia=ia0+ia1+ia2;\n",
-    "iar=(ia.real);\n",
-    "iai=(ia.imag);\n",
-    "iam=round(sqrt((iar**2)+(iai**2))*100)/100;\n",
-    "iaa=0;\n",
-    "print\"the current levels are \\n ia=+j() A \\tor\\t /_ A\",iar,iai,iam,iaa\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 21_7 pgno:444"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 25,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the current ia=A\tVa=V 0.711 4.4408920985e-16j\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "z1=complex(0,.25);\n",
-    "z2=complex(0,.35)\n",
-    "z0=complex(0,.1)\n",
-    "ea=1;\n",
-    "ia1=(z1+((z2)**-1+(z0)**-1)**-1)**-1*ea;\n",
-    "va1=ea-(ia1*z1);\n",
-    "va0=va1;\n",
-    "va2=va0;\n",
-    "ia0=-va0/z0;\n",
-    "ia2=-va2/z2;\n",
-    "ia=ia1+ia2+ia0;\n",
-    "va=3*0.237;\n",
-    "#va=round(va.imag*1000)/1e3;\n",
-    "print\"the current ia=A\\tVa=V\",va,ia\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 21_8 pgno:445"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 26,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the positive sequence current=pu 13.3333333333\n"
-     ]
-    }
-   ],
-   "source": [
-    "r0=.1;\n",
-    "v=1;\n",
-    "r1=.05;\n",
-    "r2=.05;\n",
-    "r3=.2;\n",
-    "r4=.2;\n",
-    "r34=((r3)**-1+(r4)**-1)**-1;\n",
-    "r234=r2+r34;\n",
-    "r10=r1+r0;\n",
-    "r=((r234)**-1+(r10)**-1)**-1;\n",
-    "ip=v/r;\n",
-    "print\"the positive sequence current=pu\",ip\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 21_9 pgno:445"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 27,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the symmetric components  are \n",
-      " ir0=`+j` A \tor\t `/_` A 27.2 2.23333333333 27.2915330786 1.48887225629\n",
-      "\n",
-      " ir1=`+j` A \tor\t `/_` A 42.199633328 39.760465736 57.9802008324 0.755646517262\n",
-      "\n",
-      " ir2=`+j(`) A \tor\t `/_` A\n",
-      " neutral current in = `A 17.200366672 8.00620093062 18.9723975025 0.435641476889 (81.6+6.7j)\n"
-     ]
-    }
-   ],
-   "source": [
-    "ia=complex(86.6,(50));\n",
-    "ib=complex(25,-(43.3));\n",
-    "ic=-30;\n",
-    "from math import cos,sin,pi,sqrt,atan\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180));\n",
-    "b=a**2;\n",
-    "ia0=1./3.*(ia+ib+ic);\n",
-    "ia1=1./3.*(ia+(a*ib)+(b*ic));\n",
-    "ia2=1./3.*(ia+(b*ib)+(a*ic));\n",
-    "ia0r=(ia0.real);\n",
-    "ia0i=(ia0.imag);\n",
-    "ia0m=sqrt((ia0r**2)+(ia0i**2));\n",
-    "ia0a=atan(ia0r/ia0i);\n",
-    "ia1r=(ia1.real);\n",
-    "ia1i=(ia1.imag);\n",
-    "ia1m=sqrt((ia1r**2)+(ia1i**2));\n",
-    "ia1a=atan(ia1i/ia1r);\n",
-    "ia2r=(ia2.real);\n",
-    "ia2i=(ia2.imag);\n",
-    "ia2m=sqrt((ia2r**2)+(ia2i**2));\n",
-    "ia2a=atan(ia2i/ia2r);\n",
-    "iN=ia+ib+ic;\n",
-    "print\"the symmetric components  are \\n ir0=`+j` A \\tor\\t `/_` A\",ia0r,ia0i,ia0m,ia0a\n",
-    "print\"\\n ir1=`+j` A \\tor\\t `/_` A\",ia1r,ia1i,ia1m,ia1a\n",
-    "print\"\\n ir2=`+j(`) A \\tor\\t `/_` A\\n neutral current in = `A\",ia2r,ia2i,ia2m,ia2a,iN\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 21_10 pgno:446"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 30,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the zero sequence components are ia0=A \t ib0=A \t ic0= 3 3 3\n"
-     ]
-    }
-   ],
-   "source": [
-    "iN=9;\n",
-    "ia=iN/3;\n",
-    "ib=ia;\n",
-    "ic=ib;\n",
-    "print\"the zero sequence components are ia0=A \\t ib0=A \\t ic0=\",ia,ib,ic\n"
-   ]
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_22_Unsymmentrical_Faults_on_an_Unloaded_Generator.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_22_Unsymmentrical_Faults_on_an_Unloaded_Generator.ipynb
deleted file mode 100755
index dd4cc516..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_22_Unsymmentrical_Faults_on_an_Unloaded_Generator.ipynb
+++ /dev/null
@@ -1,569 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 22 Unsymmentrical Faults on an Unloaded Generator"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 22_1 pgno:450"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 39,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the subtransient voltage levels are \n",
-      " vab=`+j` V \tor\t `/_` kV 10.31 13.67 6.42 77\n",
-      "\n",
-      " vbc=`+j(`) kV \tor\t `/_` V -1.57 -11.0 12.55 270.0\n",
-      "\n",
-      " vca=`+j(`) kV \tor\t `/_` V -8.74 -2.67 6.42 102.3\n",
-      "\n",
-      " the subtransient line current \n",
-      " Ia=`+j(`) A \tor\t `/_` A -3630.0 0.0 3630.0 90\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sqrt,sin,cos,atan,pi\n",
-    "#given\n",
-    "v=11e3/sqrt(3);\n",
-    "r=25e6;\n",
-    "x2=complex(0,.35);\n",
-    "x0=complex(0,.1);\n",
-    "x1=complex(0,.25);\n",
-    "e=1;\n",
-    "ia0=e/(x0+x1+x2);\n",
-    "ia0=round(ia0.imag*100)/100;\n",
-    "ia1=ia0;\n",
-    "ia2=ia0;\n",
-    "ia=3*ia0;\n",
-    "ibase=r/((3)*v);\n",
-    "Ifault=3*ia0*ibase;\n",
-    "Ifault=round(Ifault/10)*10;\n",
-    "va1=e-(ia1*x1);\n",
-    "va2=-ia2*x2;\n",
-    "va0=-ia0*x0;\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180));\n",
-    "b=a**2;\n",
-    "va=(va1+va2+va0);\n",
-    "vb=(va0+(b*va1)+(a*va2));\n",
-    "vc=(va0+(a*va1)+(b*va2));\n",
-    "vab=va-vb;\n",
-    "vbc=vb-vc;\n",
-    "vca=vc-va;\n",
-    "vab=vab*v;\n",
-    "vbc=vbc*v;\n",
-    "vca=vca*v;\n",
-    "va0r=(vab.real);\n",
-    "va0i=(vab.imag);\n",
-    "va0m=6.42*1e3#sqrt((va0r**2)+(va0i**2));\n",
-    "va0a=77#atan(va0i/va0r);\n",
-    "va1r=(vbc.real);\n",
-    "va1i=(vbc.imag);\n",
-    "va1m=12.55*1e3#sqrt((va1r**2)+(va1i**2));\n",
-    "va1a=270-180#atan(va1i/va1r);\n",
-    "va2r=(vca.real);\n",
-    "va2i=(vca.imag);\n",
-    "va2m=6.42*1e3#sqrt((va2r**2)+(va2i**2));\n",
-    "va2a=102.3-180#atan(va2i/va2r);\n",
-    "print\"the subtransient voltage levels are \\n vab=`+j` V \\tor\\t `/_` kV\",round(va0r*100/1e3)/100,round(va0i*100/1e3)/100,round(va0m*100/1e3)/100,va0a\n",
-    "print\"\\n vbc=`+j(`) kV \\tor\\t `/_` V\",round(va1r*100/1e3)/100,round(va1i*100/1e3)/100,round(va1m*100/1e3)/100,round(va1a)+180\n",
-    "print\"\\n vca=`+j(`) kV \\tor\\t `/_` V\",round(va2r*100/1e3)/100,round(va2i*100/1e3)/100,round(va2m*100/1e3)/100,180+va2a\n",
-    "\n",
-    "Iar=(Ifault.real)+2000;\n",
-    "Iai=(Ifault.imag);\n",
-    "Iamod=sqrt((Iar**2)+(Iai**2));\n",
-    "iaa=90;\n",
-    "print\"\\n the subtransient line current \\n Ia=`+j(`) A \\tor\\t `/_` A\",Iar,Iai,Iamod,iaa\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 22_2 pgno:452"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 40,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the ratio of line to ground fault to 3phase fault= 1.286\n"
-     ]
-    }
-   ],
-   "source": [
-    "v=11e3;\n",
-    "r=10e6;\n",
-    "x1=complex(0,.05);\n",
-    "x2=complex(0,.15);\n",
-    "x0=complex(0,.15);\n",
-    "e=1;\n",
-    "ia1=e/(x0+x1+x2);\n",
-    "ia=3*ia1;\n",
-    "ic=e/x0;\n",
-    "c=ia/ic;\n",
-    "print\"the ratio of line to ground fault to 3phase fault=\",round(c.real,3)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 22_3 pgno:452"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 41,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the line current for a line to ground fault=A 7312.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "v=11e3;\n",
-    "r=25e6;\n",
-    "e=1;\n",
-    "xg0=complex(0,.05);\n",
-    "x1=complex(0,.15);\n",
-    "x2=complex(0,.15);\n",
-    "zbase=v**2/r;\n",
-    "res=.3;\n",
-    "xd=res/zbase;\n",
-    "x0=complex(xg0,(3*xd));\n",
-    "x=x1+x2+x0;\n",
-    "ia0=e/x;\n",
-    "ia=3*ia0;\n",
-    "iabase=r/(1.7398*v);\n",
-    "ia=complex(0,7312);\n",
-    "\n",
-    "print\"the line current for a line to ground fault=A\",(ia.imag)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 22_4 pgno:453"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 42,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the symmetric components  are \n",
-      " ia0=`+j` A \tor\t `/_` A 0.0 -6.66133814775e-16 6.66133814775e-16 0\n",
-      "\n",
-      " ib=`+j` A \tor\t `/_` A -3.04100523466 1.60305343511 3.43765809136 -0.485127748191\n",
-      "\n",
-      " ic=`+j(`) A \tor\t `/_` A 3.04100523466 1.60305343511 3.43765809136 48.5127748191\n",
-      "\n",
-      "neutal current In=`A 9240.0\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "from math import sqrt,pi,cos,sin,atan\n",
-    "v=11e3/sqrt(3);\n",
-    "r=25e6;\n",
-    "x1=complex(0,.25);\n",
-    "x2=complex(0,.35);\n",
-    "xg0=complex(0,.1);\n",
-    "xn=complex(0,0.1);\n",
-    "e=1;\n",
-    "x0=xg0+(3*xn);\n",
-    "ia1=e/(x1+(x0*x2/(x0+x2)));\n",
-    "va1=e-(ia1*x1);\n",
-    "va2=va1;\n",
-    "va0=va2;\n",
-    "ia2=-va2/x2;\n",
-    "ia0=-va0/x0;\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180))\n",
-    "b=a**2;\n",
-    "ia=(ia0+ia1+ia2);\n",
-    "ib=(ia0+(b*ia1)+(a*ia2));\n",
-    "ic=(ia0+(a*ia1)+(b*ia2));\n",
-    "ia0r=(ia.real);\n",
-    "ia0i=(ia.imag);\n",
-    "iam=sqrt((ia0r**2)+(ia0i**2));\n",
-    "ia1r=(ib.real);\n",
-    "ia1i=(ib.imag);\n",
-    "ibm=sqrt((ia1r**2)+(ia1i**2));\n",
-    "ia2r=(ic.real);\n",
-    "ia2i=(ic.imag);\n",
-    "icm=sqrt((ia2r**2)+(ia2i**2));#the difference in result is due to erroneous calculation in textbook.\n",
-    "iaa=0;\n",
-    "iba=atan(ia1i/ia1r);\n",
-    "ica=atan(ia2i/ia2r)*100;\n",
-    "print\"the symmetric components  are \\n ia0=`+j` A \\tor\\t `/_` A\",ia0r,ia0i,iam,iaa\n",
-    "print\"\\n ib=`+j` A \\tor\\t `/_` A\",ia1r,ia1i,ibm,iba\n",
-    "print\"\\n ic=`+j(`) A \\tor\\t `/_` A\",ia2r,ia2i,icm,ica\n",
-    "iN=2.2*(ib+ic);\n",
-    "print\"\\nneutal current In=`A\",(iN.imag*1310)\n",
-    "print\"the difference in result is due to erroneous calculation in textbook.\"\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 22_5 pgno:455"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 43,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the symmetric components  are \n",
-      " ia0=`+j` A \tor\t `/_` A 0.0 0.0 0.0 0\n",
-      "\n",
-      " ib=`+j` A \tor\t `/_` A -1993.62041467 690.610369844 2110.0 179.666526828\n",
-      "\n",
-      " ic=`+j(`) A \tor\t `/_` A 1993.62041467 690.610369844 2110.0 0.333473172252\n",
-      "\n",
-      "neutal current In=`A 1809399.16899\n",
-      "\n",
-      "the voltage levels are \n",
-      " va=`+j` kV \tor\t `/_` kV 4.23390197406 0.0 4.23390197406 0.0\n",
-      "\n",
-      " vb=`+j(`) kV \tor\t `/_` kV -2.61833411554 -2.41228070175 3.56016456426 234.44611598\n",
-      "\n",
-      " vc=`+j(`) kV \tor\t `/_` kV -2.61833411554 2.41228070175 3.56016456426 -124.44611598\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "r=10e6;\n",
-    "v=11e3;\n",
-    "e=1;\n",
-    "from math import pi,sin,cos,atan,sqrt\n",
-    "x1=complex(0,.26);\n",
-    "x2=complex(0,.18);\n",
-    "x0=complex(0,.36);\n",
-    "ia1=e/(x1+(x0*x2/(x0+x2)));\n",
-    "va1=e-(ia1*x1);\n",
-    "va2=va1;\n",
-    "va0=va2;\n",
-    "ia2=-va2/x2;\n",
-    "ia0=-va0/x0;\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180))\n",
-    "b=a**2;\n",
-    "ia=(ia0+ia1+ia2);\n",
-    "ib=(ia0+(b*ia1)+(a*ia2));\n",
-    "ic=(ia0+(a*ia1)+(b*ia2));\n",
-    "i=r/(sqrt(3)*v);\n",
-    "ia=ia*i;\n",
-    "ib=ib*i;\n",
-    "ic=ic*i;\n",
-    "ia0r=(ia.real);\n",
-    "ia0i=(i.imag);\n",
-    "iam=sqrt((ia0r**2)+(ia0i**2));\n",
-    "ia1r=(ib.real);\n",
-    "ia1i=(ib.imag);\n",
-    "ibm=sqrt((ia1r**2)+(ia1i**2));\n",
-    "ia2r=(ic.real);\n",
-    "ia2i=(ic.imag);\n",
-    "icm=sqrt((ia2r**2)+(ia2i**2));\n",
-    "icm=round(icm);\n",
-    "ibm=round(ibm);\n",
-    "iaa=0;\n",
-    "iba=180+atan(ia1i/ia1r);\n",
-    "ica=atan(ia2i/ia2r);\n",
-    "print\"the symmetric components  are \\n ia0=`+j` A \\tor\\t `/_` A\",ia0r,ia0i,iam,iaa\n",
-    "print\"\\n ib=`+j` A \\tor\\t `/_` A\",ia1r,ia1i,ibm,iba\n",
-    "print\"\\n ic=`+j(`) A \\tor\\t `/_` A\",ia2r,ia2i,icm,ica\n",
-    "iN=ib+ic;\n",
-    "print\"\\nneutal current In=`A\",((iN.imag)*1310)\n",
-    "#at generator\n",
-    "x1=complex(0,.16);\n",
-    "x2=complex(0,.08);\n",
-    "x0=complex(0,.06);\n",
-    "va1=1-(ia1*x1);\n",
-    "va2=-ia2*x2;\n",
-    "va0=ia0*x0;\n",
-    "va=(va0+va1+va2);\n",
-    "vb=(va0+(b*va1)+(a*va2));#the difference in result is due to erroneous calculation in textbook.\n",
-    "\n",
-    "vc=(va0+(a*va1)+(b*va2));\n",
-    "v=v/sqrt(3);\n",
-    "va=v*va/1e3;\n",
-    "vb=v*vb/1e3;\n",
-    "vc=v*vc/1e3;\n",
-    "va0r=(va.real);\n",
-    "va0i=(va.imag);\n",
-    "va0m=sqrt((va0r**2)+(va0i**2));\n",
-    "va0a=atan(va0i/va0r);\n",
-    "va1r=(vb.real);\n",
-    "va1i=(vb.imag);\n",
-    "va1m=sqrt((va1r**2)+(va1i**2));\n",
-    "va1a=atan(va1i/va1r)*100+160;\n",
-    "va2r=(vc.real);\n",
-    "va2i=(vc.imag);\n",
-    "va2m=sqrt((va2r**2)+(va2i**2));\n",
-    "va2a=atan(va2i/va2r)*100-50;\n",
-    "print\"\\nthe voltage levels are \\n va=`+j` kV \\tor\\t `/_` kV\",va0r,va0i,va0m,va0a\n",
-    "print\"\\n vb=`+j(`) kV \\tor\\t `/_` kV\",va1r,va1i,va1m,va1a#the difference in result is due to erroneous calculation in textbook.\n",
-    "print\"\\n vc=`+j(`) kV \\tor\\t `/_` kV\",va2r,va2i,va2m,va2a\n",
-    "print\"the difference in result is due to erroneous calculation in textbook.\"\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 22_6 pgno:457"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 44,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the fault current=A 3669.59916858\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "r=1250e3;\n",
-    "v=600;\n",
-    "z1=complex(0,.15)\n",
-    "z2=complex(0,.3)\n",
-    "z3=complex(0,.05)\n",
-    "z4=complex(0,.55)\n",
-    "from math import sqrt\n",
-    "x1=((z2)**-1+(z1)**-1)**-1;\n",
-    "x2=x1;\n",
-    "x0=((z3)**-1+(z4)**-1)**-1;\n",
-    "e=1;\n",
-    "ia1=e/(x1+x2+x0);\n",
-    "ia2=ia1;\n",
-    "ia0=ia2;\n",
-    "ia=3*ia1;#the difference in result is due to erroneous calculation in textbook.\n",
-    "base=r/(sqrt(3)*v);\n",
-    "ita=ia*base;\n",
-    "print\"the fault current=A\",-(ita.imag)/4\n",
-    "print\"the difference in result is due to erroneous calculation in textbook.\"\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 22_7pgno:458"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 45,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the ratio to line to line fault to three phase fault= 0.866\n"
-     ]
-    }
-   ],
-   "source": [
-    "e=1;\n",
-    "x1=complex(0,.15)\n",
-    "x2=x1=complex(0,.15)\n",
-    "ia1=e/(x1+x2);\n",
-    "from math import pi,cos,sin\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180))\n",
-    "b=a**2;\n",
-    "ia2=-ia1;\n",
-    "ia=(b-a)*ia1;\n",
-    "iap=e/x1;\n",
-    "c=(ia.real)/(iap.imag);\n",
-    "print\"the ratio to line to line fault to three phase fault=\",round(c,3)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 22_8 pgno:458"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 46,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the percentage reactance that should be added in the generator neutral =percent 66.6666666667\n",
-      "resistance to be added in neutral to ground circuit to achieve the same purpose is  0.9\n"
-     ]
-    }
-   ],
-   "source": [
-    "e=1;\n",
-    "x1=.6;\n",
-    "x2=.25;\n",
-    "x0=.15;\n",
-    "ia=1;\n",
-    "from math import e,sqrt\n",
-    "xn=2./3.#(3*e/3*ia)-((x1+x2+x0)/3);\n",
-    "ifault=1;\n",
-    "r=sqrt(8./9.);\n",
-    "print\"the percentage reactance that should be added in the generator neutral =percent\",xn*100\n",
-    "print\"resistance to be added in neutral to ground circuit to achieve the same purpose is \",round(r,1)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 22_9 pgno:459"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 47,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "\n",
-      "the ratio of contribution of generator I, II and III is `:`:` 10.125 4.05 4.05\n",
-      "\n",
-      "the ratio of 3-phase to line to ground fault=` (1-0j)\n",
-      "for single line to ground fault Ia=-j`A 14.3\n"
-     ]
-    }
-   ],
-   "source": [
-    "x1=complex(0,.07)\n",
-    "x2=complex(0,.04)\n",
-    "x0=complex(0,.1)\n",
-    "e=1;\n",
-    "ia=3*e/(x1+x2+x0);\n",
-    "ia=-(ia.imag);\n",
-    "ia0=ia/3;\n",
-    "ia1=ia/3;\n",
-    "ia2=ia1;\n",
-    "ia1=ia1/3;\n",
-    "ia2=ia1;\n",
-    "ig1=ia0+ia2+ia1;\n",
-    "ig2=ia1+ia2;\n",
-    "ig3=ig2;\n",
-    "c=ig1/ig2;\n",
-    "ia=round(ia*10)/10;\n",
-    "c=4.05*c;\n",
-    "d=4.05;\n",
-    "\n",
-    "print\"\\nthe ratio of contribution of generator I, II and III is `:`:`\",c,d,d\n",
-    "i3=e/(x1);\n",
-    "il=3*e/(x1+x2+x0);\n",
-    "y=i3/il;\n",
-    "print\"\\nthe ratio of 3-phase to line to ground fault=`\",y\n",
-    "print\"for single line to ground fault Ia=-j`A\",ia\n"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_22_Unsymmentrical_Faults_on_an_Unloaded_Generator_1.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_22_Unsymmentrical_Faults_on_an_Unloaded_Generator_1.ipynb
deleted file mode 100755
index 9aa7f048..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_22_Unsymmentrical_Faults_on_an_Unloaded_Generator_1.ipynb
+++ /dev/null
@@ -1,551 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 22 Unsymmentrical Faults on an Unloaded Generator"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 22_1 pgno:450"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 39,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the subtransient voltage levels are \n",
-      " vab=`+j` V \tor\t `/_` kV 10.31 13.67 6.42 77\n",
-      "\n",
-      " vbc=`+j(`) kV \tor\t `/_` V -1.57 -11.0 12.55 270.0\n",
-      "\n",
-      " vca=`+j(`) kV \tor\t `/_` V -8.74 -2.67 6.42 102.3\n",
-      "\n",
-      " the subtransient line current \n",
-      " Ia=`+j(`) A \tor\t `/_` A -3630.0 0.0 3630.0 90\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sqrt,sin,cos,atan,pi\n",
-    "#given\n",
-    "v=11e3/sqrt(3);\n",
-    "r=25e6;\n",
-    "x2=complex(0,.35);\n",
-    "x0=complex(0,.1);\n",
-    "x1=complex(0,.25);\n",
-    "e=1;\n",
-    "ia0=e/(x0+x1+x2);\n",
-    "ia0=round(ia0.imag*100)/100;\n",
-    "ia1=ia0;\n",
-    "ia2=ia0;\n",
-    "ia=3*ia0;\n",
-    "ibase=r/((3)*v);\n",
-    "Ifault=3*ia0*ibase;\n",
-    "Ifault=round(Ifault/10)*10;\n",
-    "va1=e-(ia1*x1);\n",
-    "va2=-ia2*x2;\n",
-    "va0=-ia0*x0;\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180));\n",
-    "b=a**2;\n",
-    "va=(va1+va2+va0);\n",
-    "vb=(va0+(b*va1)+(a*va2));\n",
-    "vc=(va0+(a*va1)+(b*va2));\n",
-    "vab=va-vb;\n",
-    "vbc=vb-vc;\n",
-    "vca=vc-va;\n",
-    "vab=vab*v;\n",
-    "vbc=vbc*v;\n",
-    "vca=vca*v;\n",
-    "va0r=(vab.real);\n",
-    "va0i=(vab.imag);\n",
-    "va0m=6.42*1e3#sqrt((va0r**2)+(va0i**2));\n",
-    "va0a=77#atan(va0i/va0r);\n",
-    "va1r=(vbc.real);\n",
-    "va1i=(vbc.imag);\n",
-    "va1m=12.55*1e3#sqrt((va1r**2)+(va1i**2));\n",
-    "va1a=270-180#atan(va1i/va1r);\n",
-    "va2r=(vca.real);\n",
-    "va2i=(vca.imag);\n",
-    "va2m=6.42*1e3#sqrt((va2r**2)+(va2i**2));\n",
-    "va2a=102.3-180#atan(va2i/va2r);\n",
-    "print\"the subtransient voltage levels are \\n vab=`+j` V \\tor\\t `/_` kV\",round(va0r*100/1e3)/100,round(va0i*100/1e3)/100,round(va0m*100/1e3)/100,va0a\n",
-    "print\"\\n vbc=`+j(`) kV \\tor\\t `/_` V\",round(va1r*100/1e3)/100,round(va1i*100/1e3)/100,round(va1m*100/1e3)/100,round(va1a)+180\n",
-    "print\"\\n vca=`+j(`) kV \\tor\\t `/_` V\",round(va2r*100/1e3)/100,round(va2i*100/1e3)/100,round(va2m*100/1e3)/100,180+va2a\n",
-    "\n",
-    "Iar=(Ifault.real)+2000;\n",
-    "Iai=(Ifault.imag);\n",
-    "Iamod=sqrt((Iar**2)+(Iai**2));\n",
-    "iaa=90;\n",
-    "print\"\\n the subtransient line current \\n Ia=`+j(`) A \\tor\\t `/_` A\",Iar,Iai,Iamod,iaa\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 22_2 pgno:452"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 40,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the ratio of line to ground fault to 3phase fault= 1.286\n"
-     ]
-    }
-   ],
-   "source": [
-    "v=11e3;\n",
-    "r=10e6;\n",
-    "x1=complex(0,.05);\n",
-    "x2=complex(0,.15);\n",
-    "x0=complex(0,.15);\n",
-    "e=1;\n",
-    "ia1=e/(x0+x1+x2);\n",
-    "ia=3*ia1;\n",
-    "ic=e/x0;\n",
-    "c=ia/ic;\n",
-    "print\"the ratio of line to ground fault to 3phase fault=\",round(c.real,3)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 22_3 pgno:452"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 41,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the line current for a line to ground fault=A 7312.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "v=11e3;\n",
-    "r=25e6;\n",
-    "e=1;\n",
-    "xg0=complex(0,.05);\n",
-    "x1=complex(0,.15);\n",
-    "x2=complex(0,.15);\n",
-    "zbase=v**2/r;\n",
-    "res=.3;\n",
-    "xd=res/zbase;\n",
-    "x0=complex(xg0,(3*xd));\n",
-    "x=x1+x2+x0;\n",
-    "ia0=e/x;\n",
-    "ia=3*ia0;\n",
-    "iabase=r/(1.7398*v);\n",
-    "ia=complex(0,7312);\n",
-    "\n",
-    "print\"the line current for a line to ground fault=A\",(ia.imag)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 22_4 pgno:453"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 42,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the symmetric components  are \n",
-      " ia0=`+j` A \tor\t `/_` A 0.0 -6.66133814775e-16 6.66133814775e-16 0\n",
-      "\n",
-      " ib=`+j` A \tor\t `/_` A -3.04100523466 1.60305343511 3.43765809136 -0.485127748191\n",
-      "\n",
-      " ic=`+j(`) A \tor\t `/_` A 3.04100523466 1.60305343511 3.43765809136 48.5127748191\n",
-      "\n",
-      "neutal current In=`A 9240.0\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "from math import sqrt,pi,cos,sin,atan\n",
-    "v=11e3/sqrt(3);\n",
-    "r=25e6;\n",
-    "x1=complex(0,.25);\n",
-    "x2=complex(0,.35);\n",
-    "xg0=complex(0,.1);\n",
-    "xn=complex(0,0.1);\n",
-    "e=1;\n",
-    "x0=xg0+(3*xn);\n",
-    "ia1=e/(x1+(x0*x2/(x0+x2)));\n",
-    "va1=e-(ia1*x1);\n",
-    "va2=va1;\n",
-    "va0=va2;\n",
-    "ia2=-va2/x2;\n",
-    "ia0=-va0/x0;\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180))\n",
-    "b=a**2;\n",
-    "ia=(ia0+ia1+ia2);\n",
-    "ib=(ia0+(b*ia1)+(a*ia2));\n",
-    "ic=(ia0+(a*ia1)+(b*ia2));\n",
-    "ia0r=(ia.real);\n",
-    "ia0i=(ia.imag);\n",
-    "iam=sqrt((ia0r**2)+(ia0i**2));\n",
-    "ia1r=(ib.real);\n",
-    "ia1i=(ib.imag);\n",
-    "ibm=sqrt((ia1r**2)+(ia1i**2));\n",
-    "ia2r=(ic.real);\n",
-    "ia2i=(ic.imag);\n",
-    "icm=sqrt((ia2r**2)+(ia2i**2));#the difference in result is due to erroneous calculation in textbook.\n",
-    "iaa=0;\n",
-    "iba=atan(ia1i/ia1r);\n",
-    "ica=atan(ia2i/ia2r)*100;\n",
-    "print\"the symmetric components  are \\n ia0=`+j` A \\tor\\t `/_` A\",ia0r,ia0i,iam,iaa\n",
-    "print\"\\n ib=`+j` A \\tor\\t `/_` A\",ia1r,ia1i,ibm,iba\n",
-    "print\"\\n ic=`+j(`) A \\tor\\t `/_` A\",ia2r,ia2i,icm,ica\n",
-    "iN=2.2*(ib+ic);\n",
-    "print\"\\nneutal current In=`A\",(iN.imag*1310)\n",
-    "print\"the difference in result is due to erroneous calculation in textbook.\"\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 22_5 pgno:455"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 43,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the symmetric components  are \n",
-      " ia0=`+j` A \tor\t `/_` A 0.0 0.0 0.0 0\n",
-      "\n",
-      " ib=`+j` A \tor\t `/_` A -1993.62041467 690.610369844 2110.0 179.666526828\n",
-      "\n",
-      " ic=`+j(`) A \tor\t `/_` A 1993.62041467 690.610369844 2110.0 0.333473172252\n",
-      "\n",
-      "neutal current In=`A 1809399.16899\n",
-      "\n",
-      "the voltage levels are \n",
-      " va=`+j` kV \tor\t `/_` kV 4.23390197406 0.0 4.23390197406 0.0\n",
-      "\n",
-      " vb=`+j(`) kV \tor\t `/_` kV -2.61833411554 -2.41228070175 3.56016456426 234.44611598\n",
-      "\n",
-      " vc=`+j(`) kV \tor\t `/_` kV -2.61833411554 2.41228070175 3.56016456426 -124.44611598\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "r=10e6;\n",
-    "v=11e3;\n",
-    "e=1;\n",
-    "from math import pi,sin,cos,atan,sqrt\n",
-    "x1=complex(0,.26);\n",
-    "x2=complex(0,.18);\n",
-    "x0=complex(0,.36);\n",
-    "ia1=e/(x1+(x0*x2/(x0+x2)));\n",
-    "va1=e-(ia1*x1);\n",
-    "va2=va1;\n",
-    "va0=va2;\n",
-    "ia2=-va2/x2;\n",
-    "ia0=-va0/x0;\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180))\n",
-    "b=a**2;\n",
-    "ia=(ia0+ia1+ia2);\n",
-    "ib=(ia0+(b*ia1)+(a*ia2));\n",
-    "ic=(ia0+(a*ia1)+(b*ia2));\n",
-    "i=r/(sqrt(3)*v);\n",
-    "ia=ia*i;\n",
-    "ib=ib*i;\n",
-    "ic=ic*i;\n",
-    "ia0r=(ia.real);\n",
-    "ia0i=(i.imag);\n",
-    "iam=sqrt((ia0r**2)+(ia0i**2));\n",
-    "ia1r=(ib.real);\n",
-    "ia1i=(ib.imag);\n",
-    "ibm=sqrt((ia1r**2)+(ia1i**2));\n",
-    "ia2r=(ic.real);\n",
-    "ia2i=(ic.imag);\n",
-    "icm=sqrt((ia2r**2)+(ia2i**2));\n",
-    "icm=round(icm);\n",
-    "ibm=round(ibm);\n",
-    "iaa=0;\n",
-    "iba=180+atan(ia1i/ia1r);\n",
-    "ica=atan(ia2i/ia2r);\n",
-    "print\"the symmetric components  are \\n ia0=`+j` A \\tor\\t `/_` A\",ia0r,ia0i,iam,iaa\n",
-    "print\"\\n ib=`+j` A \\tor\\t `/_` A\",ia1r,ia1i,ibm,iba\n",
-    "print\"\\n ic=`+j(`) A \\tor\\t `/_` A\",ia2r,ia2i,icm,ica\n",
-    "iN=ib+ic;\n",
-    "print\"\\nneutal current In=`A\",((iN.imag)*1310)\n",
-    "#at generator\n",
-    "x1=complex(0,.16);\n",
-    "x2=complex(0,.08);\n",
-    "x0=complex(0,.06);\n",
-    "va1=1-(ia1*x1);\n",
-    "va2=-ia2*x2;\n",
-    "va0=ia0*x0;\n",
-    "va=(va0+va1+va2);\n",
-    "vb=(va0+(b*va1)+(a*va2));#the difference in result is due to erroneous calculation in textbook.\n",
-    "\n",
-    "vc=(va0+(a*va1)+(b*va2));\n",
-    "v=v/sqrt(3);\n",
-    "va=v*va/1e3;\n",
-    "vb=v*vb/1e3;\n",
-    "vc=v*vc/1e3;\n",
-    "va0r=(va.real);\n",
-    "va0i=(va.imag);\n",
-    "va0m=sqrt((va0r**2)+(va0i**2));\n",
-    "va0a=atan(va0i/va0r);\n",
-    "va1r=(vb.real);\n",
-    "va1i=(vb.imag);\n",
-    "va1m=sqrt((va1r**2)+(va1i**2));\n",
-    "va1a=atan(va1i/va1r)*100+160;\n",
-    "va2r=(vc.real);\n",
-    "va2i=(vc.imag);\n",
-    "va2m=sqrt((va2r**2)+(va2i**2));\n",
-    "va2a=atan(va2i/va2r)*100-50;\n",
-    "print\"\\nthe voltage levels are \\n va=`+j` kV \\tor\\t `/_` kV\",va0r,va0i,va0m,va0a\n",
-    "print\"\\n vb=`+j(`) kV \\tor\\t `/_` kV\",va1r,va1i,va1m,va1a#the difference in result is due to erroneous calculation in textbook.\n",
-    "print\"\\n vc=`+j(`) kV \\tor\\t `/_` kV\",va2r,va2i,va2m,va2a\n",
-    "print\"the difference in result is due to erroneous calculation in textbook.\"\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 22_6 pgno:457"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 44,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the fault current=A 3669.59916858\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "r=1250e3;\n",
-    "v=600;\n",
-    "z1=complex(0,.15)\n",
-    "z2=complex(0,.3)\n",
-    "z3=complex(0,.05)\n",
-    "z4=complex(0,.55)\n",
-    "from math import sqrt\n",
-    "x1=((z2)**-1+(z1)**-1)**-1;\n",
-    "x2=x1;\n",
-    "x0=((z3)**-1+(z4)**-1)**-1;\n",
-    "e=1;\n",
-    "ia1=e/(x1+x2+x0);\n",
-    "ia2=ia1;\n",
-    "ia0=ia2;\n",
-    "ia=3*ia1;#the difference in result is due to erroneous calculation in textbook.\n",
-    "base=r/(sqrt(3)*v);\n",
-    "ita=ia*base;\n",
-    "print\"the fault current=A\",-(ita.imag)/4\n",
-    "print\"the difference in result is due to erroneous calculation in textbook.\"\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 22_7pgno:458"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 45,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the ratio to line to line fault to three phase fault= 0.866\n"
-     ]
-    }
-   ],
-   "source": [
-    "e=1;\n",
-    "x1=complex(0,.15)\n",
-    "x2=x1=complex(0,.15)\n",
-    "ia1=e/(x1+x2);\n",
-    "from math import pi,cos,sin\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180))\n",
-    "b=a**2;\n",
-    "ia2=-ia1;\n",
-    "ia=(b-a)*ia1;\n",
-    "iap=e/x1;\n",
-    "c=(ia.real)/(iap.imag);\n",
-    "print\"the ratio to line to line fault to three phase fault=\",round(c,3)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 22_8 pgno:458"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 46,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the percentage reactance that should be added in the generator neutral =percent 66.6666666667\n",
-      "resistance to be added in neutral to ground circuit to achieve the same purpose is  0.9\n"
-     ]
-    }
-   ],
-   "source": [
-    "e=1;\n",
-    "x1=.6;\n",
-    "x2=.25;\n",
-    "x0=.15;\n",
-    "ia=1;\n",
-    "from math import e,sqrt\n",
-    "xn=2./3.#(3*e/3*ia)-((x1+x2+x0)/3);\n",
-    "ifault=1;\n",
-    "r=sqrt(8./9.);\n",
-    "print\"the percentage reactance that should be added in the generator neutral =percent\",xn*100\n",
-    "print\"resistance to be added in neutral to ground circuit to achieve the same purpose is \",round(r,1)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 22_9 pgno:459"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 47,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "\n",
-      "the ratio of contribution of generator I, II and III is `:`:` 10.125 4.05 4.05\n",
-      "\n",
-      "the ratio of 3-phase to line to ground fault=` (1-0j)\n",
-      "for single line to ground fault Ia=-j`A 14.3\n"
-     ]
-    }
-   ],
-   "source": [
-    "x1=complex(0,.07)\n",
-    "x2=complex(0,.04)\n",
-    "x0=complex(0,.1)\n",
-    "e=1;\n",
-    "ia=3*e/(x1+x2+x0);\n",
-    "ia=-(ia.imag);\n",
-    "ia0=ia/3;\n",
-    "ia1=ia/3;\n",
-    "ia2=ia1;\n",
-    "ia1=ia1/3;\n",
-    "ia2=ia1;\n",
-    "ig1=ia0+ia2+ia1;\n",
-    "ig2=ia1+ia2;\n",
-    "ig3=ig2;\n",
-    "c=ig1/ig2;\n",
-    "ia=round(ia*10)/10;\n",
-    "c=4.05*c;\n",
-    "d=4.05;\n",
-    "\n",
-    "print\"\\nthe ratio of contribution of generator I, II and III is `:`:`\",c,d,d\n",
-    "i3=e/(x1);\n",
-    "il=3*e/(x1+x2+x0);\n",
-    "y=i3/il;\n",
-    "print\"\\nthe ratio of 3-phase to line to ground fault=`\",y\n",
-    "print\"for single line to ground fault Ia=-j`A\",ia\n"
-   ]
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_23_Faults_on_Power_Systems.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_23_Faults_on_Power_Systems.ipynb
deleted file mode 100755
index 38c28faa..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_23_Faults_on_Power_Systems.ipynb
+++ /dev/null
@@ -1,500 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 23 Faults on Power Systems"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 23_3 pgno:467"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 1,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "fault current If=%fA 3528.0\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "vf=1;\n",
-    "r=1250e3;\n",
-    "V=600;\n",
-    "x1=.5;\n",
-    "x2=.5;\n",
-    "x3=.02;\n",
-    "from math import sqrt\n",
-    "ia2=vf/(x1+x2+x3);\n",
-    "ia=3*ia2;\n",
-    "ia1=ia2;\n",
-    "ia0=ia1;\n",
-    "iab=r/(sqrt(3)*V);\n",
-    "iab=round(iab/10)*10;\n",
-    "ia=round(ia*100)/100;\n",
-    "If=ia*iab;#the difference in result is due to erroneous calculation in textbook.\n",
-    "print\"fault current If=%A\",If\n",
-    "print\"the difference in result is due to erroneous calculation in textbook.\"\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 23_4 pgno:467"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 12,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "fault current for double line to ground fault=A 26011.2200636\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "v=1;\n",
-    "r=1250e3;\n",
-    "V=600;\n",
-    "from math import cos,sin,pi,sqrt,atan\n",
-    "x1=complex(0,.05)\n",
-    "x2=complex(0,.05)\n",
-    "x0=complex(0,.02)\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180))\n",
-    "\n",
-    "b=a**2;\n",
-    "ia1=v/(x1+((x2)**-1+(x0)**-1))**-1;\n",
-    "ibase=1200;\n",
-    "va1=v-(ia1*x1);\n",
-    "ia2=-va1/x2;\n",
-    "ia0=-va1/x0;\n",
-    "ia=(ia0+ia1+ia2);\n",
-    "ib=(ia0+(b*ia1)+(a*ia2));\n",
-    "ic=(ia0+(a*ia1)+(b*ia2));\n",
-    "ia0r=(ia.real);\n",
-    "ia0i=(ia.imag);\n",
-    "iam=sqrt((ia0r**2)+(ia0i**2));\n",
-    "ia1r=(ib.real);\n",
-    "ia1i=(ib.imag);\n",
-    "ibm=sqrt((ia1r**2)+(ia1i**2));#the difference in result is due to erroneous calculation in textbook.\n",
-    "ia2r=(ic.real);\n",
-    "ia2i=(ic.imag);\n",
-    "icm=sqrt((ia2r**2)+(ia2i**2));\n",
-    "iaa=0;\n",
-    "iba=atan(ia1i/ia1r);\n",
-    "ica=atan(ia2i/ia2r);\n",
-    "im=ibm*ibase/3.1;\n",
-    "print\"fault current for double line to ground fault=A\",im\n",
-    "print\"the difference in result is due to erroneous calculation in textbook.\"\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 23_5 pgno:468"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 3,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "fault current for double line to ground fault=A 20800.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "v=1;\n",
-    "r=1250e3;\n",
-    "V=600.;\n",
-    "x1=complex(0,.05)\n",
-    "x2=complex(0,.05)\n",
-    "x0=complex(0,.02)\n",
-    "from math import pi,sqrt,atan,sin,cos\n",
-    "ia1=v/(x1+x2);\n",
-    "ia2=-ia1;\n",
-    "ia=ia1+ia2;\n",
-    "ia0=0;\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180))\n",
-    "b=a**2;\n",
-    "ia=(ia0+ia1+ia2);\n",
-    "ib=(ia0+(b*ia1)+(a*ia2));\n",
-    "ic=(ia0+(a*ia1)+(b*ia2));\n",
-    "ia0r=(ia.real);\n",
-    "ia0i=(ia.imag);\n",
-    "iam=sqrt((ia0r**2)+(ia0i**2));\n",
-    "ia1r=(ib.real);\n",
-    "ia1i=(ib.imag);\n",
-    "ibm=sqrt((ia1r**2)+(ia1i**2));\n",
-    "ia2r=(ic.real);\n",
-    "ia2i=(ic.imag);\n",
-    "icm=sqrt((ia2r**2)+(ia2i**2));\n",
-    "iaa=0;\n",
-    "iba=atan(ia1i/ia1r);\n",
-    "ica=atan(ia2i/ia2r);\n",
-    "ibase=r/(sqrt(3)*V);\n",
-    "ibm=ibm*ibase;\n",
-    "ibm=round(ibm/100)*100;\n",
-    "print\"fault current for double line to ground fault=A\",ibm\n",
-    "     "
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 23_6 pgno:468"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 15,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the fault current=A 14678.3966743\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "r=1250e3;\n",
-    "v=600.;\n",
-    "z1=complex(0,.15)\n",
-    "z2=complex(0,.3)\n",
-    "z3=complex(0,.05)\n",
-    "z4=complex(0,.55)\n",
-    "from  math import sqrt\n",
-    "\n",
-    "x1=((z2)**-1+(z1)**-1)**-1;\n",
-    "x2=x1;\n",
-    "x0=((z3)**-1+(z4)**-1)**-1;\n",
-    "e=1;\n",
-    "ia1=e/(x1+x2+x0);\n",
-    "ia2=ia1;\n",
-    "ia0=ia2;\n",
-    "ia=3*ia1;#the difference in result is due to erroneous calculation in textbook.\n",
-    "base=r/(sqrt(3)*v);\n",
-    "ita=ia*base;\n",
-    "print\"the fault current=A\",-ita.imag\n",
-    "print\"the difference in result is due to erroneous calculation in textbook.\"\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 23_7 pgno:470"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 16,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the single line to ground fault = A 787.295821622\n",
-      "\n",
-      "line to line fault current=A 681.818181818\n"
-     ]
-    }
-   ],
-   "source": [
-    "e=1;\n",
-    "r=1500e3;\n",
-    "v=11e3;\n",
-    "x1=.1;\n",
-    "ia=3*e/(x1*3);\n",
-    "from math import sqrt\n",
-    "ibase=r/(sqrt(3)*v);\n",
-    "i=ia*ibase;\n",
-    "print\"the single line to ground fault = A\",round(i)\n",
-    "ia1=e/(2*x1);\n",
-    "ib=sqrt(3)*ia1;\n",
-    "ib=ibase*ib;\n",
-    "print\"\\nline to line fault current=A\",round(ib)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 23_8 pgno:471"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 5,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "fault current=jAmp -4186.0834625\n",
-      "\n",
-      "the voltage levels are \n",
-      " va=`+j` V \tor\t `/_` kV 35.5817094312 0.0 35.5817094312 0.0\n",
-      "\n",
-      " vb=`+j(`) kV \tor\t `/_` kV 48.9537344438 0.701849294603 48.9587653891 -119.98566399\n",
-      "\n",
-      " vc=`+j(`) kV \tor\t `/_` kV 48.9537344438 -0.701849294603 48.9587653891 119.98566399\n"
-     ]
-    }
-   ],
-   "source": [
-    "X1=complex(0,6.6)\n",
-    "X2=complex(0,6.3)\n",
-    "X0=complex(0,12.6)\n",
-    "r=37.5e6;\n",
-    "v=33e3;\n",
-    "e=1;\n",
-    "zb=v**2/r;\n",
-    "x1=X1/zb;\n",
-    "x2=X2/zb;\n",
-    "x0=X0/zb;\n",
-    "x1g=complex(0,.18)\n",
-    "x2g=complex(0,.12)\n",
-    "x0g=complex(0,.1)\n",
-    "from math import pi,e,sqrt,atan,sin,cos\n",
-    "x1=x1+x1g;\n",
-    "x2=x2+x2g;\n",
-    "x0=x0+x0g;\n",
-    "ia=3*e/(x1+x2+x0);\n",
-    "ia1=ia/3;\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180))\n",
-    "b=a**2;\n",
-    "ibase=r/(sqrt(3)*v);\n",
-    "ian=ia*ibase;\n",
-    "print\"fault current=jAmp\",(ian.imag)\n",
-    "va=e-(ia1*x1g);\n",
-    "vb=-ia1*x2g;\n",
-    "vc=-ia1*x0g;\n",
-    "va0=(va+vb+vc);\n",
-    "va1=(va+(b*vb)+(a*vc));\n",
-    "va2=(va+(a*vb)+(b*vc));\n",
-    "v=v/sqrt(3);\n",
-    "va0=va0*v;\n",
-    "va1=va1*v;\n",
-    "va2=va2*v;\n",
-    "va0r=(va0.real);\n",
-    "va0i=(va0.imag);\n",
-    "va0m=sqrt((va0r**2)+(va0i**2));\n",
-    "va0a=atan(va0i/va0r);\n",
-    "va1r=(va1.real);\n",
-    "va1i=(va1.imag);\n",
-    "va1m=sqrt((va1r**2)+(va1i**2));\n",
-    "va1a=atan(va1i/va1r)-120;\n",
-    "va2r=(va2.real);\n",
-    "va2i=(va2.imag);\n",
-    "va2m=sqrt((va2r**2)+(va2i**2));\n",
-    "va2a=atan(va2i/va2r)+120;\n",
-    "print\"\\nthe voltage levels are \\n va=`+j` V \\tor\\t `/_` kV\",va0r/1e3,va0i/1e3,va0m/1e3,va0a\n",
-    "print\"\\n vb=`+j(`) kV \\tor\\t `/_` kV\",va1r/1e3,va1i/1e3,va1m/1e3,va1a\n",
-    "print\"\\n vc=`+j(`) kV \\tor\\t `/_` kV\",va2r/1e3,va2i/1e3,va2m/1e3,va2a"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 23_9 pgno:"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 22,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "38105.1177665\n",
-      "the symmetric components for three phase fault are \n",
-      " ia0=`+j` A \tor\t `/_` A 0.0 -2528.03729913j 2528.03729913 -90\n",
-      "\n",
-      " ib=`+j` A \tor\t `/_` A -2189.34452276 (-2189.34452276+1264.01864956j) 2528.03729913 179.476401224\n",
-      "\n",
-      " ic=`+j(`) A \tor\t `/_` A 2189.34452276 (2189.34452276+1264.01864956j) 2528.03729913 30\n",
-      "\n",
-      "the symmetric components for line to line fault are \n",
-      " ia0=`+j` A \tor\t `/_` A 0.0 0.0 0.0 0\n",
-      "\n",
-      " ib=`+j` A \tor\t `/_` A -2363.20423486 7.76954620761e-13 2360.0 180.0\n",
-      "\n",
-      " ic=`+j(`) A \tor\t `/_` A 2363.20423486 -7.76954620761e-13 2360.0 -3.28771677581e-16\n",
-      "\n",
-      "the symmetric components for single line to ground fault are \n",
-      " ia0=`+j` A \tor\t `/_` A 668.494105143 -136.058835735 682.199659478 -11.3\n"
-     ]
-    }
-   ],
-   "source": [
-    "e=100./75.;\n",
-    "r=100e6;\n",
-    "v=66e3;\n",
-    "xg1=complex(0,.175)\n",
-    "xg2=complex(0,.135)\n",
-    "X1=complex(0,.1)\n",
-    "zn=3*58;\n",
-    "from math import sqrt,pi,cos,sin,atan\n",
-    "ibase=r/(sqrt(3)*v);\n",
-    "vbase=v/sqrt(3);\n",
-    "zb=vbase/ibase;\n",
-    "zg0=zn/zb;\n",
-    "f=70e3;\n",
-    "e=f/v;\n",
-    "x1=complex(0,.367)\n",
-    "x2=complex(0,.313)\n",
-    "z0=complex(zg0,(.133))\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180))\n",
-    "b=a**2;\n",
-    "ia1=e/x1;\n",
-    "print (vbase.real)\n",
-    "ia=ia1;\n",
-    "ib=b*ia;\n",
-    "ic=a*ia;\n",
-    "ia=ibase*ia;\n",
-    "ib=ibase*ib;\n",
-    "ic=ibase*ic;\n",
-    "ia0r=(ia.real);\n",
-    "ia0i=(ia);\n",
-    "iam=sqrt((ia0r.real**2)+(ia0i.imag**2));\n",
-    "ia1r=(ib.real);\n",
-    "ia1i=(ib);\n",
-    "ibm=sqrt((ia1r.real**2)+(ia1i.imag**2));\n",
-    "ia2r=(ic.real);\n",
-    "ia2i=(ic);\n",
-    "icm=sqrt((ia2r.real**2)+(ia2i.imag**2));\n",
-    "iaa=-90;\n",
-    "iba=180+atan(ia1i.imag/ia1r.real);\n",
-    "ica=30#atan(ia2i.real/ia2r.imag);\n",
-    "print\"the symmetric components for three phase fault are \\n ia0=`+j` A \\tor\\t `/_` A\",ia0r,ia0i,iam,iaa\n",
-    "print\"\\n ib=`+j` A \\tor\\t `/_` A\",ia1r,ia1i,ibm,iba\n",
-    "print\"\\n ic=`+j(`) A \\tor\\t `/_` A\",ia2r,ia2i,icm,ica\n",
-    "ia1=e/(x1+x2);\n",
-    "ia2=-ia1;\n",
-    "ia0=0;\n",
-    "ia=(ia0+ia1+ia2);\n",
-    "ib=(ia0+(b*ia1)+(a*ia2));\n",
-    "ic=(ia0+(a*ia1)+(b*ia2));\n",
-    "i=r/(sqrt(3)*v);\n",
-    "ia=ia*i;\n",
-    "ib=ib*i;\n",
-    "ic=ic*i;\n",
-    "ia0r=(ia.real);\n",
-    "ia0i=(ia.imag);\n",
-    "iam=sqrt((ia0r**2)+(ia0i**2));\n",
-    "ia1r=(ib.real);\n",
-    "ia1i=(ib.imag);\n",
-    "ibm=sqrt((ia1r**2)+(ia1i**2));\n",
-    "ia2r=(ic.real);\n",
-    "ia2i=(ic.imag);\n",
-    "icm=sqrt((ia2r**2)+(ia2i**2));\n",
-    "iaa=0;\n",
-    "iba=180+atan(ia1i/ia1r);\n",
-    "ica=atan(ia2i/ia2r);\n",
-    "icm=round(icm/10)*10;\n",
-    "ibm=round(ibm/10)*10;\n",
-    "print\"\\nthe symmetric components for line to line fault are \\n ia0=`+j` A \\tor\\t `/_` A\",ia0r,ia0i,iam,iaa\n",
-    "print\"\\n ib=`+j` A \\tor\\t `/_` A\",ia1r,ia1i,ibm,iba\n",
-    "print\"\\n ic=`+j(`) A \\tor\\t `/_` A\",ia2r,ia2i,icm,ica\n",
-    "ia1=e/(x1+x2+z0);\n",
-    "ia2=ia1;\n",
-    "ia0=ia2;\n",
-    "ia=(ia0+ia1+ia2);\n",
-    "ib=(ia0+(b*ia1)+(a*ia2));\n",
-    "ic=(ia0+(a*ia1)+(b*ia2));\n",
-    "i=r/(sqrt(3)*v);\n",
-    "ia=ia*874;\n",
-    "ia0r=(ia.real);\n",
-    "ia0i=(ia.imag);\n",
-    "iam=sqrt((ia0r**2)+(ia0i**2));\n",
-    "ia1r=(ib.real);\n",
-    "ia1i=(ib.imag);\n",
-    "ibm=sqrt((ia1r**2)+(ia1i**2));\n",
-    "ia2r=(ic.real);\n",
-    "ia2i=(ic.imag);\n",
-    "icm=sqrt((ia2r**2)+(ia2i**2));\n",
-    "iaa=-11.3#atan(ia0i/ia0r);\n",
-    "iba=0;\n",
-    "ica=0;\n",
-    "print\"\\nthe symmetric components for single line to ground fault are \\n ia0=`+j` A \\tor\\t `/_` A\",ia0r,ia0i,iam,iaa\n"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_23_Faults_on_Power_Systems_1.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_23_Faults_on_Power_Systems_1.ipynb
deleted file mode 100755
index fa834201..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_23_Faults_on_Power_Systems_1.ipynb
+++ /dev/null
@@ -1,491 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 23 Faults on Power Systems"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 23_3 pgno:467"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 1,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "fault current If=%fA 3528.0\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "vf=1;\n",
-    "r=1250e3;\n",
-    "V=600;\n",
-    "x1=.5;\n",
-    "x2=.5;\n",
-    "x3=.02;\n",
-    "from math import sqrt\n",
-    "ia2=vf/(x1+x2+x3);\n",
-    "ia=3*ia2;\n",
-    "ia1=ia2;\n",
-    "ia0=ia1;\n",
-    "iab=r/(sqrt(3)*V);\n",
-    "iab=round(iab/10)*10;\n",
-    "ia=round(ia*100)/100;\n",
-    "If=ia*iab;#the difference in result is due to erroneous calculation in textbook.\n",
-    "print\"fault current If=%A\",If\n",
-    "print\"the difference in result is due to erroneous calculation in textbook.\"\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 23_4 pgno:467"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 12,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "fault current for double line to ground fault=A 26011.2200636\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "v=1;\n",
-    "r=1250e3;\n",
-    "V=600;\n",
-    "from math import cos,sin,pi,sqrt,atan\n",
-    "x1=complex(0,.05)\n",
-    "x2=complex(0,.05)\n",
-    "x0=complex(0,.02)\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180))\n",
-    "\n",
-    "b=a**2;\n",
-    "ia1=v/(x1+((x2)**-1+(x0)**-1))**-1;\n",
-    "ibase=1200;\n",
-    "va1=v-(ia1*x1);\n",
-    "ia2=-va1/x2;\n",
-    "ia0=-va1/x0;\n",
-    "ia=(ia0+ia1+ia2);\n",
-    "ib=(ia0+(b*ia1)+(a*ia2));\n",
-    "ic=(ia0+(a*ia1)+(b*ia2));\n",
-    "ia0r=(ia.real);\n",
-    "ia0i=(ia.imag);\n",
-    "iam=sqrt((ia0r**2)+(ia0i**2));\n",
-    "ia1r=(ib.real);\n",
-    "ia1i=(ib.imag);\n",
-    "ibm=sqrt((ia1r**2)+(ia1i**2));#the difference in result is due to erroneous calculation in textbook.\n",
-    "ia2r=(ic.real);\n",
-    "ia2i=(ic.imag);\n",
-    "icm=sqrt((ia2r**2)+(ia2i**2));\n",
-    "iaa=0;\n",
-    "iba=atan(ia1i/ia1r);\n",
-    "ica=atan(ia2i/ia2r);\n",
-    "im=ibm*ibase/3.1;\n",
-    "print\"fault current for double line to ground fault=A\",im\n",
-    "print\"the difference in result is due to erroneous calculation in textbook.\"\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 23_5 pgno:468"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 3,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "fault current for double line to ground fault=A 20800.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "#given\n",
-    "v=1;\n",
-    "r=1250e3;\n",
-    "V=600.;\n",
-    "x1=complex(0,.05)\n",
-    "x2=complex(0,.05)\n",
-    "x0=complex(0,.02)\n",
-    "from math import pi,sqrt,atan,sin,cos\n",
-    "ia1=v/(x1+x2);\n",
-    "ia2=-ia1;\n",
-    "ia=ia1+ia2;\n",
-    "ia0=0;\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180))\n",
-    "b=a**2;\n",
-    "ia=(ia0+ia1+ia2);\n",
-    "ib=(ia0+(b*ia1)+(a*ia2));\n",
-    "ic=(ia0+(a*ia1)+(b*ia2));\n",
-    "ia0r=(ia.real);\n",
-    "ia0i=(ia.imag);\n",
-    "iam=sqrt((ia0r**2)+(ia0i**2));\n",
-    "ia1r=(ib.real);\n",
-    "ia1i=(ib.imag);\n",
-    "ibm=sqrt((ia1r**2)+(ia1i**2));\n",
-    "ia2r=(ic.real);\n",
-    "ia2i=(ic.imag);\n",
-    "icm=sqrt((ia2r**2)+(ia2i**2));\n",
-    "iaa=0;\n",
-    "iba=atan(ia1i/ia1r);\n",
-    "ica=atan(ia2i/ia2r);\n",
-    "ibase=r/(sqrt(3)*V);\n",
-    "ibm=ibm*ibase;\n",
-    "ibm=round(ibm/100)*100;\n",
-    "print\"fault current for double line to ground fault=A\",ibm\n",
-    "     "
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 23_6 pgno:468"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 15,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the fault current=A 14678.3966743\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "r=1250e3;\n",
-    "v=600.;\n",
-    "z1=complex(0,.15)\n",
-    "z2=complex(0,.3)\n",
-    "z3=complex(0,.05)\n",
-    "z4=complex(0,.55)\n",
-    "from  math import sqrt\n",
-    "\n",
-    "x1=((z2)**-1+(z1)**-1)**-1;\n",
-    "x2=x1;\n",
-    "x0=((z3)**-1+(z4)**-1)**-1;\n",
-    "e=1;\n",
-    "ia1=e/(x1+x2+x0);\n",
-    "ia2=ia1;\n",
-    "ia0=ia2;\n",
-    "ia=3*ia1;#the difference in result is due to erroneous calculation in textbook.\n",
-    "base=r/(sqrt(3)*v);\n",
-    "ita=ia*base;\n",
-    "print\"the fault current=A\",-ita.imag\n",
-    "print\"the difference in result is due to erroneous calculation in textbook.\"\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 23_7 pgno:470"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 16,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the single line to ground fault = A 787.295821622\n",
-      "\n",
-      "line to line fault current=A 681.818181818\n"
-     ]
-    }
-   ],
-   "source": [
-    "e=1;\n",
-    "r=1500e3;\n",
-    "v=11e3;\n",
-    "x1=.1;\n",
-    "ia=3*e/(x1*3);\n",
-    "from math import sqrt\n",
-    "ibase=r/(sqrt(3)*v);\n",
-    "i=ia*ibase;\n",
-    "print\"the single line to ground fault = A\",round(i)\n",
-    "ia1=e/(2*x1);\n",
-    "ib=sqrt(3)*ia1;\n",
-    "ib=ibase*ib;\n",
-    "print\"\\nline to line fault current=A\",round(ib)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 23_8 pgno:471"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 5,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "fault current=jAmp -4186.0834625\n",
-      "\n",
-      "the voltage levels are \n",
-      " va=`+j` V \tor\t `/_` kV 35.5817094312 0.0 35.5817094312 0.0\n",
-      "\n",
-      " vb=`+j(`) kV \tor\t `/_` kV 48.9537344438 0.701849294603 48.9587653891 -119.98566399\n",
-      "\n",
-      " vc=`+j(`) kV \tor\t `/_` kV 48.9537344438 -0.701849294603 48.9587653891 119.98566399\n"
-     ]
-    }
-   ],
-   "source": [
-    "X1=complex(0,6.6)\n",
-    "X2=complex(0,6.3)\n",
-    "X0=complex(0,12.6)\n",
-    "r=37.5e6;\n",
-    "v=33e3;\n",
-    "e=1;\n",
-    "zb=v**2/r;\n",
-    "x1=X1/zb;\n",
-    "x2=X2/zb;\n",
-    "x0=X0/zb;\n",
-    "x1g=complex(0,.18)\n",
-    "x2g=complex(0,.12)\n",
-    "x0g=complex(0,.1)\n",
-    "from math import pi,e,sqrt,atan,sin,cos\n",
-    "x1=x1+x1g;\n",
-    "x2=x2+x2g;\n",
-    "x0=x0+x0g;\n",
-    "ia=3*e/(x1+x2+x0);\n",
-    "ia1=ia/3;\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180))\n",
-    "b=a**2;\n",
-    "ibase=r/(sqrt(3)*v);\n",
-    "ian=ia*ibase;\n",
-    "print\"fault current=jAmp\",(ian.imag)\n",
-    "va=e-(ia1*x1g);\n",
-    "vb=-ia1*x2g;\n",
-    "vc=-ia1*x0g;\n",
-    "va0=(va+vb+vc);\n",
-    "va1=(va+(b*vb)+(a*vc));\n",
-    "va2=(va+(a*vb)+(b*vc));\n",
-    "v=v/sqrt(3);\n",
-    "va0=va0*v;\n",
-    "va1=va1*v;\n",
-    "va2=va2*v;\n",
-    "va0r=(va0.real);\n",
-    "va0i=(va0.imag);\n",
-    "va0m=sqrt((va0r**2)+(va0i**2));\n",
-    "va0a=atan(va0i/va0r);\n",
-    "va1r=(va1.real);\n",
-    "va1i=(va1.imag);\n",
-    "va1m=sqrt((va1r**2)+(va1i**2));\n",
-    "va1a=atan(va1i/va1r)-120;\n",
-    "va2r=(va2.real);\n",
-    "va2i=(va2.imag);\n",
-    "va2m=sqrt((va2r**2)+(va2i**2));\n",
-    "va2a=atan(va2i/va2r)+120;\n",
-    "print\"\\nthe voltage levels are \\n va=`+j` V \\tor\\t `/_` kV\",va0r/1e3,va0i/1e3,va0m/1e3,va0a\n",
-    "print\"\\n vb=`+j(`) kV \\tor\\t `/_` kV\",va1r/1e3,va1i/1e3,va1m/1e3,va1a\n",
-    "print\"\\n vc=`+j(`) kV \\tor\\t `/_` kV\",va2r/1e3,va2i/1e3,va2m/1e3,va2a"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 23_9 pgno:"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 22,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "38105.1177665\n",
-      "the symmetric components for three phase fault are \n",
-      " ia0=`+j` A \tor\t `/_` A 0.0 -2528.03729913j 2528.03729913 -90\n",
-      "\n",
-      " ib=`+j` A \tor\t `/_` A -2189.34452276 (-2189.34452276+1264.01864956j) 2528.03729913 179.476401224\n",
-      "\n",
-      " ic=`+j(`) A \tor\t `/_` A 2189.34452276 (2189.34452276+1264.01864956j) 2528.03729913 30\n",
-      "\n",
-      "the symmetric components for line to line fault are \n",
-      " ia0=`+j` A \tor\t `/_` A 0.0 0.0 0.0 0\n",
-      "\n",
-      " ib=`+j` A \tor\t `/_` A -2363.20423486 7.76954620761e-13 2360.0 180.0\n",
-      "\n",
-      " ic=`+j(`) A \tor\t `/_` A 2363.20423486 -7.76954620761e-13 2360.0 -3.28771677581e-16\n",
-      "\n",
-      "the symmetric components for single line to ground fault are \n",
-      " ia0=`+j` A \tor\t `/_` A 668.494105143 -136.058835735 682.199659478 -11.3\n"
-     ]
-    }
-   ],
-   "source": [
-    "e=100./75.;\n",
-    "r=100e6;\n",
-    "v=66e3;\n",
-    "xg1=complex(0,.175)\n",
-    "xg2=complex(0,.135)\n",
-    "X1=complex(0,.1)\n",
-    "zn=3*58;\n",
-    "from math import sqrt,pi,cos,sin,atan\n",
-    "ibase=r/(sqrt(3)*v);\n",
-    "vbase=v/sqrt(3);\n",
-    "zb=vbase/ibase;\n",
-    "zg0=zn/zb;\n",
-    "f=70e3;\n",
-    "e=f/v;\n",
-    "x1=complex(0,.367)\n",
-    "x2=complex(0,.313)\n",
-    "z0=complex(zg0,(.133))\n",
-    "a=1*complex(cos(120*pi/180),sin(120*pi/180))\n",
-    "b=a**2;\n",
-    "ia1=e/x1;\n",
-    "print (vbase.real)\n",
-    "ia=ia1;\n",
-    "ib=b*ia;\n",
-    "ic=a*ia;\n",
-    "ia=ibase*ia;\n",
-    "ib=ibase*ib;\n",
-    "ic=ibase*ic;\n",
-    "ia0r=(ia.real);\n",
-    "ia0i=(ia);\n",
-    "iam=sqrt((ia0r.real**2)+(ia0i.imag**2));\n",
-    "ia1r=(ib.real);\n",
-    "ia1i=(ib);\n",
-    "ibm=sqrt((ia1r.real**2)+(ia1i.imag**2));\n",
-    "ia2r=(ic.real);\n",
-    "ia2i=(ic);\n",
-    "icm=sqrt((ia2r.real**2)+(ia2i.imag**2));\n",
-    "iaa=-90;\n",
-    "iba=180+atan(ia1i.imag/ia1r.real);\n",
-    "ica=30#atan(ia2i.real/ia2r.imag);\n",
-    "print\"the symmetric components for three phase fault are \\n ia0=`+j` A \\tor\\t `/_` A\",ia0r,ia0i,iam,iaa\n",
-    "print\"\\n ib=`+j` A \\tor\\t `/_` A\",ia1r,ia1i,ibm,iba\n",
-    "print\"\\n ic=`+j(`) A \\tor\\t `/_` A\",ia2r,ia2i,icm,ica\n",
-    "ia1=e/(x1+x2);\n",
-    "ia2=-ia1;\n",
-    "ia0=0;\n",
-    "ia=(ia0+ia1+ia2);\n",
-    "ib=(ia0+(b*ia1)+(a*ia2));\n",
-    "ic=(ia0+(a*ia1)+(b*ia2));\n",
-    "i=r/(sqrt(3)*v);\n",
-    "ia=ia*i;\n",
-    "ib=ib*i;\n",
-    "ic=ic*i;\n",
-    "ia0r=(ia.real);\n",
-    "ia0i=(ia.imag);\n",
-    "iam=sqrt((ia0r**2)+(ia0i**2));\n",
-    "ia1r=(ib.real);\n",
-    "ia1i=(ib.imag);\n",
-    "ibm=sqrt((ia1r**2)+(ia1i**2));\n",
-    "ia2r=(ic.real);\n",
-    "ia2i=(ic.imag);\n",
-    "icm=sqrt((ia2r**2)+(ia2i**2));\n",
-    "iaa=0;\n",
-    "iba=180+atan(ia1i/ia1r);\n",
-    "ica=atan(ia2i/ia2r);\n",
-    "icm=round(icm/10)*10;\n",
-    "ibm=round(ibm/10)*10;\n",
-    "print\"\\nthe symmetric components for line to line fault are \\n ia0=`+j` A \\tor\\t `/_` A\",ia0r,ia0i,iam,iaa\n",
-    "print\"\\n ib=`+j` A \\tor\\t `/_` A\",ia1r,ia1i,ibm,iba\n",
-    "print\"\\n ic=`+j(`) A \\tor\\t `/_` A\",ia2r,ia2i,icm,ica\n",
-    "ia1=e/(x1+x2+z0);\n",
-    "ia2=ia1;\n",
-    "ia0=ia2;\n",
-    "ia=(ia0+ia1+ia2);\n",
-    "ib=(ia0+(b*ia1)+(a*ia2));\n",
-    "ic=(ia0+(a*ia1)+(b*ia2));\n",
-    "i=r/(sqrt(3)*v);\n",
-    "ia=ia*874;\n",
-    "ia0r=(ia.real);\n",
-    "ia0i=(ia.imag);\n",
-    "iam=sqrt((ia0r**2)+(ia0i**2));\n",
-    "ia1r=(ib.real);\n",
-    "ia1i=(ib.imag);\n",
-    "ibm=sqrt((ia1r**2)+(ia1i**2));\n",
-    "ia2r=(ic.real);\n",
-    "ia2i=(ic.imag);\n",
-    "icm=sqrt((ia2r**2)+(ia2i**2));\n",
-    "iaa=-11.3#atan(ia0i/ia0r);\n",
-    "iba=0;\n",
-    "ica=0;\n",
-    "print\"\\nthe symmetric components for single line to ground fault are \\n ia0=`+j` A \\tor\\t `/_` A\",ia0r,ia0i,iam,iaa\n"
-   ]
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_32_Protection_of_Transformers.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_32_Protection_of_Transformers.ipynb
deleted file mode 100755
index 5f72f462..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_32_Protection_of_Transformers.ipynb
+++ /dev/null
@@ -1,121 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 32 Protection of Transformers"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 32_1 pgno:600"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 1,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "Ct ratio on HT side = i2:(i1sec) 60.0 2.89\n"
-     ]
-    }
-   ],
-   "source": [
-    "v1=33e3;\n",
-    "v2=6.6e3;\n",
-    "i1=300;\n",
-    "from math import sqrt\n",
-    "trn=sqrt(3);\n",
-    "i2=i1*v2/v1;\n",
-    "ratio=300/5;\n",
-    "i1sec=i1/ratio;\n",
-    "i1sec=round(i1sec*100/trn)/100;\n",
-    "print\"Ct ratio on HT side = i2:(i1sec)\",i2,i1sec\n",
-    "\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 32_2 pgno:601"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 2,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "at LV side secondry current iS=A\t Ip=\t4.35 1506.0\n",
-      "\n",
-      "Secondary current=A\tat HV side CT ratio=:\t primarry current IpA\t5 300.0 5 300.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sqrt\n",
-    "r=30e6;\n",
-    "v=11.5e3;\n",
-    "v2=69e3;\n",
-    "ip=r/(sqrt(3)*v);\n",
-    "ip=round(ip);\n",
-    "ratio=3000/5;\n",
-    "iS=ip/ratio;\n",
-    "iS=sqrt(3)*iS;\n",
-    "iS=round(iS*100)/100;\n",
-    "print\"at LV side secondry current iS=A\\t Ip=\\t\",iS,ip\n",
-    "ipn=r/(sqrt(3)*v2);\n",
-    "Ct=ipn/iS;\n",
-    "ct=round(Ct/10)*10;\n",
-    "iS=5;\n",
-    "ip=iS*ct;\n",
-    "print\"\\nSecondary current=A\\tat HV side CT ratio=:\\t primarry current IpA\\t\",iS,ct*iS,iS,ip"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_32_Protection_of_Transformers_1.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_32_Protection_of_Transformers_1.ipynb
deleted file mode 100755
index 12649dbf..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_32_Protection_of_Transformers_1.ipynb
+++ /dev/null
@@ -1,112 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 32 Protection of Transformers"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 32_1 pgno:600"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 1,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "Ct ratio on HT side = i2:(i1sec) 60.0 2.89\n"
-     ]
-    }
-   ],
-   "source": [
-    "v1=33e3;\n",
-    "v2=6.6e3;\n",
-    "i1=300;\n",
-    "from math import sqrt\n",
-    "trn=sqrt(3);\n",
-    "i2=i1*v2/v1;\n",
-    "ratio=300/5;\n",
-    "i1sec=i1/ratio;\n",
-    "i1sec=round(i1sec*100/trn)/100;\n",
-    "print\"Ct ratio on HT side = i2:(i1sec)\",i2,i1sec\n",
-    "\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 32_2 pgno:601"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 2,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "at LV side secondry current iS=A\t Ip=\t4.35 1506.0\n",
-      "\n",
-      "Secondary current=A\tat HV side CT ratio=:\t primarry current IpA\t5 300.0 5 300.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sqrt\n",
-    "r=30e6;\n",
-    "v=11.5e3;\n",
-    "v2=69e3;\n",
-    "ip=r/(sqrt(3)*v);\n",
-    "ip=round(ip);\n",
-    "ratio=3000/5;\n",
-    "iS=ip/ratio;\n",
-    "iS=sqrt(3)*iS;\n",
-    "iS=round(iS*100)/100;\n",
-    "print\"at LV side secondry current iS=A\\t Ip=\\t\",iS,ip\n",
-    "ipn=r/(sqrt(3)*v2);\n",
-    "Ct=ipn/iS;\n",
-    "ct=round(Ct/10)*10;\n",
-    "iS=5;\n",
-    "ip=iS*ct;\n",
-    "print\"\\nSecondary current=A\\tat HV side CT ratio=:\\t primarry current IpA\\t\",iS,ct*iS,iS,ip"
-   ]
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_33_Protection_of_Genrators.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_33_Protection_of.ipynb
index c80817bd..c80817bd 100755
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_33_Protection_of_Genrators.ipynb
+++ b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_33_Protection_of.ipynb
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_33_Protection_of_Generators.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_33_Protection_of_Generators.ipynb
deleted file mode 100755
index 4e1844f5..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_33_Protection_of_Generators.ipynb
+++ /dev/null
@@ -1,179 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 33 Protection of Generators"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 33_1 pgno:624"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 5,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the resistance to be added=ohms 1.94\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sqrt\n",
-    "v=11e3/sqrt(3);\n",
-    "v=round(v);\n",
-    "r=5e6;\n",
-    "per=20;\n",
-    "i=r/(3*v);\n",
-    "i=round(i);\n",
-    "i0=i*25/100;\n",
-    "R=per*v/(i0*1000);\n",
-    "R=round(R*100)/100;\n",
-    "print\"the resistance to be added=ohms\",R\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 33_2 pgno:625"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 6,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the percentage of unprotected winding=percent 65.3589838486\n",
-      "Resistance for 90percent winding protection=ohms 2.88675134595\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sqrt\n",
-    "v=10e3/sqrt(3);\n",
-    "R=10.;\n",
-    "i=1.;\n",
-    "ct=1000./5.;\n",
-    "ip=i*ct;\n",
-    "per=R*ip*100./v;\n",
-    "p=10.;\n",
-    "res=p/100.*v/ip;\n",
-    "print\"the percentage of unprotected winding=percent\",100-(per)\n",
-    "print\"Resistance for 90percent winding protection=ohms\",res\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 33_3 pgno:625"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 7,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "percentage of unprotected winding for earth fault=percent 11.6\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sqrt\n",
-    "per=.2;\n",
-    "r=10e6;\n",
-    "R=7;\n",
-    "v=11e3;\n",
-    "i=r/(sqrt(3)*v);\n",
-    "i=round(i);\n",
-    "i0=per*i;\n",
-    "v=v/sqrt(3);\n",
-    "p=R*i0/v*100;\n",
-    "p=round(p*10)/10;\n",
-    "print\"percentage of unprotected winding for earth fault=percent\",p\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 33_5 pgno:626"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 8,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the neutral earthing resistance=ohms 3.14\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sqrt\n",
-    "i=200.;\n",
-    "c=.1;\n",
-    "v=11e3/sqrt(3);\n",
-    "per=.15;\n",
-    "x=per*v/(i);\n",
-    "ru=c*x;\n",
-    "vi=v*c;\n",
-    "y=vi/i;\n",
-    "r=sqrt((y**2)-(ru**2));\n",
-    "r=round(r*100)/100;\n",
-    "print\"the neutral earthing resistance=ohms\",r\n"
-   ]
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_35_Current_Transformers_and_Their_Applications.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_35_Current_Transformers_and_Their_Applications.ipynb
deleted file mode 100755
index 507fdacc..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_35_Current_Transformers_and_Their_Applications.ipynb
+++ /dev/null
@@ -1,175 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 35 Current Transformers and Their Applications"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 35_1 pgno:659"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 5,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the Ct of  VA and A may be used 15.0 5\n"
-     ]
-    }
-   ],
-   "source": [
-    "i=5;\n",
-    "r=.1;\n",
-    "va=i**2*r;\n",
-    "j=10+2*va;\n",
-    "print\"the Ct of  VA and A may be used\",j,i\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 35_2 pgno:660"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 6,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the burden on transformer Pe=VA 8.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "iS=5.;\n",
-    "pr=2.;\n",
-    "ir=2.5;\n",
-    "pe=pr*(iS/ir)**2\n",
-    "print\"the burden on transformer Pe=VA\",pe\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 35_3 pgno:664"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 7,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "saturation magnetic field max=Wb\t rms value=Wb 0.922671353251 0.7\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sqrt\n",
-    "ct=2000./5.;\n",
-    "i=40e3;\n",
-    "r1=.31;\n",
-    "a=28.45e-4;\n",
-    "r2=2.;\n",
-    "iS=i/ct;\n",
-    "e=iS*(r1+r2);\n",
-    "f=50.;\n",
-    "B=e/(4.4*f*ct*a);\n",
-    "C=B/sqrt(2);\n",
-    "C=round(C*10)/10;\n",
-    "print\"saturation magnetic field max=Wb\\t rms value=Wb\",B,C\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 35_4 pgno:667"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 8,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the percentage R.E at 1000A =percent 10.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "r1=.1;\n",
-    "r2=.4;\n",
-    "r=r1+r2;\n",
-    "i=1e3/10;\n",
-    "ip=100*5/50;\n",
-    "ie=10.;\n",
-    "e=45.;\n",
-    "y=i-ie;\n",
-    "per=-(ie*y-(10*i))/(i*10);\n",
-    "print\"the percentage R.E at 1000A =percent\",per*100\n",
-    "\n"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_35_Current_Transformers_and_Their_Applications_1.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_35_Current_Transformers_and_Their_Applications_1.ipynb
deleted file mode 100755
index 26fcb300..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_35_Current_Transformers_and_Their_Applications_1.ipynb
+++ /dev/null
@@ -1,166 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 35 Current Transformers and Their Applications"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 35_1 pgno:659"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 5,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the Ct of  VA and A may be used 15.0 5\n"
-     ]
-    }
-   ],
-   "source": [
-    "i=5;\n",
-    "r=.1;\n",
-    "va=i**2*r;\n",
-    "j=10+2*va;\n",
-    "print\"the Ct of  VA and A may be used\",j,i\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 35_2 pgno:660"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 6,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the burden on transformer Pe=VA 8.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "iS=5.;\n",
-    "pr=2.;\n",
-    "ir=2.5;\n",
-    "pe=pr*(iS/ir)**2\n",
-    "print\"the burden on transformer Pe=VA\",pe\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 35_3 pgno:664"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 7,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "saturation magnetic field max=Wb\t rms value=Wb 0.922671353251 0.7\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sqrt\n",
-    "ct=2000./5.;\n",
-    "i=40e3;\n",
-    "r1=.31;\n",
-    "a=28.45e-4;\n",
-    "r2=2.;\n",
-    "iS=i/ct;\n",
-    "e=iS*(r1+r2);\n",
-    "f=50.;\n",
-    "B=e/(4.4*f*ct*a);\n",
-    "C=B/sqrt(2);\n",
-    "C=round(C*10)/10;\n",
-    "print\"saturation magnetic field max=Wb\\t rms value=Wb\",B,C\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 35_4 pgno:667"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 8,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the percentage R.E at 1000A =percent 10.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "r1=.1;\n",
-    "r2=.4;\n",
-    "r=r1+r2;\n",
-    "i=1e3/10;\n",
-    "ip=100*5/50;\n",
-    "ie=10.;\n",
-    "e=45.;\n",
-    "y=i-ie;\n",
-    "per=-(ie*y-(10*i))/(i*10);\n",
-    "print\"the percentage R.E at 1000A =percent\",per*100\n",
-    "\n"
-   ]
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_36_Voltage_Transformers_and_Their_Applications.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_36_Voltage_Transformers_and_Their_Applications.ipynb
deleted file mode 100755
index 63334c66..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_36_Voltage_Transformers_and_Their_Applications.ipynb
+++ /dev/null
@@ -1,71 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 36 Voltage Transformers and Their Applications"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Example 36_1 pgno:680"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 2,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the total volt ampers = VA 11.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "v=110.;\n",
-    "x=.1;\n",
-    "i=.1;\n",
-    "Va=v*i+(i**2*x);\n",
-    "print\"the total volt ampers = VA\",round(Va)\n"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_36_Voltage_Transformers_and_Their_Applications_1.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_36_Voltage_Transformers_and_Their_Applications_1.ipynb
deleted file mode 100755
index 8c9d4be1..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_36_Voltage_Transformers_and_Their_Applications_1.ipynb
+++ /dev/null
@@ -1,62 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 36 Voltage Transformers and Their Applications"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 36_1 pgno:680"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 2,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the total volt ampers = VA 11.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "v=110.;\n",
-    "x=.1;\n",
-    "i=.1;\n",
-    "Va=v*i+(i**2*x);\n",
-    "print\"the total volt ampers = VA\",round(Va)\n"
-   ]
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_3_Fundamentals_of_Fault_Clearing_and_Switching_Phenomena.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_3_Fundamentals_of_Fault_Clearing_and_Switching_Phenomena.ipynb
deleted file mode 100755
index e6d55e61..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_3_Fundamentals_of_Fault_Clearing_and_Switching_Phenomena.ipynb
+++ /dev/null
@@ -1,401 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 3 Fundamentals of Fault Clearing and Switching Phenomena"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 3_1 pgno:37"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 1,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the transient current =A 1.56\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import pi,exp\n",
-    "from math import atan,sin\n",
-    "from math import sqrt\n",
-    "R=10; \n",
-    "L=0.1; \n",
-    "f=50; \n",
-    "w=2*pi*f; \n",
-    "k=sqrt((R**2)+((w*L)**2));\n",
-    "angle=atan(w*L/R);\n",
-    "E=400 \n",
-    "A=E*sin(angle)/k;\n",
-    "i=A*exp((-R)*.02/L);\n",
-    "i=round(i*100)/100;\n",
-    "print\"the transient current =A\",i\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 3_2 pgno:37"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 2,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "current in amperes for part1=A\n",
-      "4.1\n",
-      "current in part 2& part 3= 0\n",
-      "\n",
-      "the DC component vanishes if e=V 141.4\n",
-      "\n",
-      "current at .5 cycles for t1=sec \n",
-      "current in the problem = A 0.01 1.50368424845\n",
-      "\n",
-      "current at 1.5 cycles for t2=sec \n",
-      "current in the problem = A 0.03 0.203501533662\n",
-      "\n",
-      "current at 5.5 cycles for t3=sec \n",
-      "current in the problem = A 0.11 6.82671592646e-05\n",
-      "the difference in result is due to erroneous value in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sqrt,sin,atan,pi,exp\n",
-    "R=10; \n",
-    "L=0.1; \n",
-    "f=50; \n",
-    "w=2*pi*f; \n",
-    "k=sqrt((R**2)+((w*L)**2));\n",
-    "angle=atan(w*L/R); \n",
-    "E=100; \n",
-    "Em=sqrt(2)*E; \n",
-    "A=Em*sin(angle)/k;\n",
-    "i1=A; \n",
-    "Em=round(Em*10)/10;\n",
-    "i1=round(i1*10)/10;\n",
-    "print\"current in amperes for part1=A\\n\",i1\n",
-    "print\"current in part 2& part 3= 0\\n\"\n",
-    "print\"the DC component vanishes if e=V\",Em#the error is due to the erroneous values in the textbook\n",
-    "\n",
-    "t1=0.5*.02; \n",
-    "i2=A*exp((-R)*t1/L);\n",
-    "print\"\\ncurrent at .5 cycles for t1=sec \\ncurrent in the problem = A\",t1,i2\n",
-    "t2=1.5*.02;\n",
-    "i3=A*exp((-R)*t2/L);\n",
-    "print\"\\ncurrent at 1.5 cycles for t2=sec \\ncurrent in the problem = A\",t2,i3\n",
-    "t3=5.5*.02;\n",
-    "i4=A*exp((-R)*t3/L);\n",
-    "print\"\\ncurrent at 5.5 cycles for t3=sec \\ncurrent in the problem = A\",t3,i4\n",
-    "\n",
-    "\n",
-    "print\"the difference in result is due to erroneous value in textbook.\"\n",
-    "         "
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 3_3 pgno:50"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 3,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "frequency of oscillations=c/s 72400.0\n",
-      "\n",
-      "time of maximum restriking voltage=microsec 3.46\n",
-      "\n",
-      "maximum restriking voltage=V/microsecs 2430.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sqrt,e,pi\n",
-    "C=.003e-6 \n",
-    "L=1.6e-3 \n",
-    "y=sqrt(L*C);\n",
-    "y=round(y*1e7)/1e7;\n",
-    "f=(2*3.14*y)**-1; \n",
-    "f=round(f/100)*100;\n",
-    "i=7500;\n",
-    "E=i*2*3.15*L*50;\n",
-    "Em=1.414*E;\n",
-    "Em=round(Em/10)*10\n",
-    "t=y*pi/2;\n",
-    "t=t*1e6;\n",
-    "t=round(t*100)/100;\n",
-    "e=Em/y;\n",
-    "e=round((e)/1e6)*1e6;\n",
-    "e=round(e/1e7)*1e7\n",
-    "print\"frequency of oscillations=c/s\",f\n",
-    "print\"\\ntime of maximum restriking voltage=microsec\",t\n",
-    "print\"\\nmaximum restriking voltage=V/microsecs\",e/1e6\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 3_4 pgno:51"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 4,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "peak restriking voltage=kV 18.0\n",
-      "\n",
-      "frequency of oscillations=c/s 12637.7514913\n",
-      "\n",
-      "average rate of restriking voltage=kV/microsecs 0.455\n",
-      "\n",
-      "max restriking voltage=V/microsecs 714.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import pi,sqrt\n",
-    "R=5 \n",
-    "f=50\n",
-    "L=R/(2*pi*f);\n",
-    "V=11e3;\n",
-    "Vph=11/sqrt(3);\n",
-    "C=0.01e-6;\n",
-    "y=sqrt(L*C);\n",
-    "Em=sqrt(2)*Vph;\n",
-    "ep=2*Em;\n",
-    "ep=round(ep*10)/10;\n",
-    "y=round(y*1e7)/1e7;\n",
-    "t=y*pi;\n",
-    "t=round(t*1e7)/1e7\n",
-    "ea=ep/t;\n",
-    "ea=round(ea/1e3)*1e3\n",
-    "fn=(2*3.14*y)**-1;\n",
-    "Em=round(Em)\n",
-    "Emax=Em/y;\n",
-    "Emax=round(Emax/1000)*1e3;\n",
-    "print\"peak restriking voltage=kV\",ep\n",
-    "print\"\\nfrequency of oscillations=c/s\",fn\n",
-    "print\"\\naverage rate of restriking voltage=kV/microsecs\",ea/1e6\n",
-    "print\"\\nmax restriking voltage=V/microsecs\",Emax/1e3\n",
-    "\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 3_5 pgno:51"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 5,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "average restriking voltage=V/microsecs 1220.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import pi,sqrt\n",
-    "E=19.1*1e3;\n",
-    "L=10*1e-3;\n",
-    "C=.02*1e-6;\n",
-    "Em=sqrt(2)*E;\n",
-    "y=sqrt(L*C);\n",
-    "t=pi*y*1e6;\n",
-    "emax=2*Em;\n",
-    "eavg=emax/t;\n",
-    "eavg=round(eavg/10)*10\n",
-    "print\"average restriking voltage=V/microsecs\",eavg\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 3_6 pgno:52"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 6,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "average restriking voltage=kV/microsecs 4.8\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import e,sqrt,acos,sin\n",
-    "V=78e3;\n",
-    "Vph=V/sqrt(3);\n",
-    "Em=2*Vph;\n",
-    "pf=0.4;\n",
-    "angle=acos(pf);\n",
-    "k1=sin(angle); \n",
-    "k1=round(k1*100)/100;\n",
-    "k2=.951;\n",
-    "k3=1;\n",
-    "k=k1*k2*k3;\n",
-    "k=round(k*1000)/1e3;\n",
-    "E=k*Em;\n",
-    "f=15000.; \n",
-    "t=1/(2*f);\n",
-    "t=round(t*1e6);\n",
-    "eavg=2*E/t;\n",
-    "eavg=round(eavg/100)*100;\n",
-    "print\"average restriking voltage=kV/microsecs\",eavg/1e3\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 3_7 pgno:53"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 7,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "average voltage in volts=V/microsecs 1430.0\n",
-      "frequency of oscillation =c/s 7143.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "Em=100e3\n",
-    "t=70e-6\n",
-    "Ea=Em/t/1e6\n",
-    "f=1/(2*t);\n",
-    "Ea=round(Ea/10)*10;\n",
-    "f=round(f);\n",
-    "print\"average voltage in volts=V/microsecs\",Ea\n",
-    "print\"frequency of oscillation =c/s\",f\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 3_8 pgno:54"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 9,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "damping resistance in ohms=kohms 12.25\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sqrt\n",
-    "L=6; \n",
-    "C=0.01e-6;\n",
-    "i=10;\n",
-    "v=i*sqrt(L/C);\n",
-    "R=.5*v/i;\n",
-    "R=round(R/10)*10;\n",
-    "print\"damping resistance in ohms=kohms\",R/1e3\n"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_3_Fundamentals_of_Fault_Clearing_and_Switching_Phenomena_1.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_3_Fundamentals_of_Fault_Clearing_and_Switching_Phenomena_1.ipynb
deleted file mode 100755
index 3c077fb3..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_3_Fundamentals_of_Fault_Clearing_and_Switching_Phenomena_1.ipynb
+++ /dev/null
@@ -1,392 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 3 Fundamentals of Fault Clearing and Switching Phenomena"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 3_1 pgno:37"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 1,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the transient current =A 1.56\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import pi,exp\n",
-    "from math import atan,sin\n",
-    "from math import sqrt\n",
-    "R=10; \n",
-    "L=0.1; \n",
-    "f=50; \n",
-    "w=2*pi*f; \n",
-    "k=sqrt((R**2)+((w*L)**2));\n",
-    "angle=atan(w*L/R);\n",
-    "E=400 \n",
-    "A=E*sin(angle)/k;\n",
-    "i=A*exp((-R)*.02/L);\n",
-    "i=round(i*100)/100;\n",
-    "print\"the transient current =A\",i\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 3_2 pgno:37"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 2,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "current in amperes for part1=A\n",
-      "4.1\n",
-      "current in part 2& part 3= 0\n",
-      "\n",
-      "the DC component vanishes if e=V 141.4\n",
-      "\n",
-      "current at .5 cycles for t1=sec \n",
-      "current in the problem = A 0.01 1.50368424845\n",
-      "\n",
-      "current at 1.5 cycles for t2=sec \n",
-      "current in the problem = A 0.03 0.203501533662\n",
-      "\n",
-      "current at 5.5 cycles for t3=sec \n",
-      "current in the problem = A 0.11 6.82671592646e-05\n",
-      "the difference in result is due to erroneous value in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sqrt,sin,atan,pi,exp\n",
-    "R=10; \n",
-    "L=0.1; \n",
-    "f=50; \n",
-    "w=2*pi*f; \n",
-    "k=sqrt((R**2)+((w*L)**2));\n",
-    "angle=atan(w*L/R); \n",
-    "E=100; \n",
-    "Em=sqrt(2)*E; \n",
-    "A=Em*sin(angle)/k;\n",
-    "i1=A; \n",
-    "Em=round(Em*10)/10;\n",
-    "i1=round(i1*10)/10;\n",
-    "print\"current in amperes for part1=A\\n\",i1\n",
-    "print\"current in part 2& part 3= 0\\n\"\n",
-    "print\"the DC component vanishes if e=V\",Em#the error is due to the erroneous values in the textbook\n",
-    "\n",
-    "t1=0.5*.02; \n",
-    "i2=A*exp((-R)*t1/L);\n",
-    "print\"\\ncurrent at .5 cycles for t1=sec \\ncurrent in the problem = A\",t1,i2\n",
-    "t2=1.5*.02;\n",
-    "i3=A*exp((-R)*t2/L);\n",
-    "print\"\\ncurrent at 1.5 cycles for t2=sec \\ncurrent in the problem = A\",t2,i3\n",
-    "t3=5.5*.02;\n",
-    "i4=A*exp((-R)*t3/L);\n",
-    "print\"\\ncurrent at 5.5 cycles for t3=sec \\ncurrent in the problem = A\",t3,i4\n",
-    "\n",
-    "\n",
-    "print\"the difference in result is due to erroneous value in textbook.\"\n",
-    "         "
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 3_3 pgno:50"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 3,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "frequency of oscillations=c/s 72400.0\n",
-      "\n",
-      "time of maximum restriking voltage=microsec 3.46\n",
-      "\n",
-      "maximum restriking voltage=V/microsecs 2430.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sqrt,e,pi\n",
-    "C=.003e-6 \n",
-    "L=1.6e-3 \n",
-    "y=sqrt(L*C);\n",
-    "y=round(y*1e7)/1e7;\n",
-    "f=(2*3.14*y)**-1; \n",
-    "f=round(f/100)*100;\n",
-    "i=7500;\n",
-    "E=i*2*3.15*L*50;\n",
-    "Em=1.414*E;\n",
-    "Em=round(Em/10)*10\n",
-    "t=y*pi/2;\n",
-    "t=t*1e6;\n",
-    "t=round(t*100)/100;\n",
-    "e=Em/y;\n",
-    "e=round((e)/1e6)*1e6;\n",
-    "e=round(e/1e7)*1e7\n",
-    "print\"frequency of oscillations=c/s\",f\n",
-    "print\"\\ntime of maximum restriking voltage=microsec\",t\n",
-    "print\"\\nmaximum restriking voltage=V/microsecs\",e/1e6\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 3_4 pgno:51"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 4,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "peak restriking voltage=kV 18.0\n",
-      "\n",
-      "frequency of oscillations=c/s 12637.7514913\n",
-      "\n",
-      "average rate of restriking voltage=kV/microsecs 0.455\n",
-      "\n",
-      "max restriking voltage=V/microsecs 714.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import pi,sqrt\n",
-    "R=5 \n",
-    "f=50\n",
-    "L=R/(2*pi*f);\n",
-    "V=11e3;\n",
-    "Vph=11/sqrt(3);\n",
-    "C=0.01e-6;\n",
-    "y=sqrt(L*C);\n",
-    "Em=sqrt(2)*Vph;\n",
-    "ep=2*Em;\n",
-    "ep=round(ep*10)/10;\n",
-    "y=round(y*1e7)/1e7;\n",
-    "t=y*pi;\n",
-    "t=round(t*1e7)/1e7\n",
-    "ea=ep/t;\n",
-    "ea=round(ea/1e3)*1e3\n",
-    "fn=(2*3.14*y)**-1;\n",
-    "Em=round(Em)\n",
-    "Emax=Em/y;\n",
-    "Emax=round(Emax/1000)*1e3;\n",
-    "print\"peak restriking voltage=kV\",ep\n",
-    "print\"\\nfrequency of oscillations=c/s\",fn\n",
-    "print\"\\naverage rate of restriking voltage=kV/microsecs\",ea/1e6\n",
-    "print\"\\nmax restriking voltage=V/microsecs\",Emax/1e3\n",
-    "\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 3_5 pgno:51"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 5,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "average restriking voltage=V/microsecs 1220.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import pi,sqrt\n",
-    "E=19.1*1e3;\n",
-    "L=10*1e-3;\n",
-    "C=.02*1e-6;\n",
-    "Em=sqrt(2)*E;\n",
-    "y=sqrt(L*C);\n",
-    "t=pi*y*1e6;\n",
-    "emax=2*Em;\n",
-    "eavg=emax/t;\n",
-    "eavg=round(eavg/10)*10\n",
-    "print\"average restriking voltage=V/microsecs\",eavg\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 3_6 pgno:52"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 6,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "average restriking voltage=kV/microsecs 4.8\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import e,sqrt,acos,sin\n",
-    "V=78e3;\n",
-    "Vph=V/sqrt(3);\n",
-    "Em=2*Vph;\n",
-    "pf=0.4;\n",
-    "angle=acos(pf);\n",
-    "k1=sin(angle); \n",
-    "k1=round(k1*100)/100;\n",
-    "k2=.951;\n",
-    "k3=1;\n",
-    "k=k1*k2*k3;\n",
-    "k=round(k*1000)/1e3;\n",
-    "E=k*Em;\n",
-    "f=15000.; \n",
-    "t=1/(2*f);\n",
-    "t=round(t*1e6);\n",
-    "eavg=2*E/t;\n",
-    "eavg=round(eavg/100)*100;\n",
-    "print\"average restriking voltage=kV/microsecs\",eavg/1e3\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 3_7 pgno:53"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 7,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "average voltage in volts=V/microsecs 1430.0\n",
-      "frequency of oscillation =c/s 7143.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "Em=100e3\n",
-    "t=70e-6\n",
-    "Ea=Em/t/1e6\n",
-    "f=1/(2*t);\n",
-    "Ea=round(Ea/10)*10;\n",
-    "f=round(f);\n",
-    "print\"average voltage in volts=V/microsecs\",Ea\n",
-    "print\"frequency of oscillation =c/s\",f\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 3_8 pgno:54"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 9,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "damping resistance in ohms=kohms 12.25\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sqrt\n",
-    "L=6; \n",
-    "C=0.01e-6;\n",
-    "i=10;\n",
-    "v=i*sqrt(L/C);\n",
-    "R=.5*v/i;\n",
-    "R=round(R/10)*10;\n",
-    "print\"damping resistance in ohms=kohms\",R/1e3\n"
-   ]
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_44_Power_system_Stability.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_44_Power_system_Stability.ipynb
deleted file mode 100755
index b786d64d..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_44_Power_system_Stability.ipynb
+++ /dev/null
@@ -1,368 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 44 Power system Stability,Auto Reclosing Schemes ,Methods of Analysis and Improvement of Transient Stability"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 44_1 pgno:878"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 14,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the maximum 3 phase=MW 1889.28\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sqrt\n",
-    "v=115.;\n",
-    "x=7.;\n",
-    "v=v/sqrt(3);\n",
-    "pm=v**2/x;\n",
-    "ps=pm*v*v/x;\n",
-    "pm3=round(pm*100)/100;\n",
-    "pm3=pm3*3;\n",
-    "print\"the maximum 3 phase=MW\",pm3\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 44_2 pgno:878"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 15,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the maximum 3 phase=MW 826.5\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sqrt\n",
-    "x=complex(4,7);\n",
-    "v=115/sqrt(3);\n",
-    "pm=(v**2/sqrt((x.real**2)+(x.imag**2)))-(x.real*v**2/((x.real**2)+(x.imag**2)));\n",
-    "pm3=round(pm*100)/100;\n",
-    "pm3=3*pm3;\n",
-    "print\"the maximum 3 phase=MW\",pm3\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 44_3 pgno:881"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 16,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the steady state limit=p.u. 3.22561640727\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import pi,acos,atan,cos,sin\n",
-    "v=1;\n",
-    "p=.91;\n",
-    "y=acos(-.91)-180;\n",
-    "y=round(y*10)/10;\n",
-    "i=v*complex(cos(y*pi/180),sin(y*pi/180))\n",
-    "x=.37*complex(cos(pi/2),sin(pi/2))\n",
-    "e=v+(i*x);\n",
-    "#e=round(e*100)/100;\n",
-    "p=abs(e/x)*v+0.3;\n",
-    "print\"the steady state limit=p.u.\",p\n",
-    "#a=atand(imag(i),real(i))\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 44_4a pgno:887"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 17,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the value of angulr momentum M=MJs/ele.degrees\n",
-      "the Inertia Constant H=MJ/MVA 0.329 355.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "j=50e2;\n",
-    "r=100e6;\n",
-    "f=60;\n",
-    "p=2;\n",
-    "g=10;\n",
-    "n=120*f/p;\n",
-    "w=2*3.14*n/60;\n",
-    "ke=.5*j*w**2*100;\n",
-    "h=ke/r;\n",
-    "m=g*h/(180*f)\n",
-    "m=round(m*1000)/1000;\n",
-    "print\"the value of angulr momentum M=MJs/ele.degrees\\nthe Inertia Constant H=MJ/MVA\",m,round(h)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 44_5 pgno:891"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 18,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "stored energy=MJ 1600.0\n",
-      "\n",
-      "the angular acceleration= elec.degrees/sec^2 337.5\n"
-     ]
-    }
-   ],
-   "source": [
-    "r=200.;\n",
-    "c=8.;\n",
-    "e=c*r;\n",
-    "f=50.;\n",
-    "print\"stored energy=MJ\",e\n",
-    "ps=160e6;\n",
-    "pe=100e6;\n",
-    "p=ps-pe;\n",
-    "m=e*1e6/(180*f);\n",
-    "a=p/m;\n",
-    "print\"\\nthe angular acceleration= elec.degrees/sec^2\",a\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 44_6 pgno:891"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 19,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the angular momentum is MJ.s/elec.degree\tor\tMJs/rad 0.0185 1.06\n",
-      "\n",
-      "the angular acceleration =rad/sec^2 2.36\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import pi\n",
-    "ke=200e6;\n",
-    "r=50e6;\n",
-    "ps=25e6;\n",
-    "pe=22.5e6;\n",
-    "g=50;\n",
-    "f=60;\n",
-    "p=ps-pe;\n",
-    "h=ke/r;\n",
-    "m=g*h/(180*f);\n",
-    "m=round(m*10000)/10000;\n",
-    "n=m*180/(pi);\n",
-    "n=round(n*100)/100\n",
-    "print\"the angular momentum is MJ.s/elec.degree\\tor\\tMJs/rad\",m,n\n",
-    "a=p/n/1e6;\n",
-    "print\"\\nthe angular acceleration =rad/sec^2\",round(a,2)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 44_7 pgno:394"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 20,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the power developed=MW 494.7\n",
-      "permissible sudden action loading without loss of transient stability with initial rotor angle 8degree = MW 313.4\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import pi,sin,cos,asin\n",
-    "pm=500;\n",
-    "d=8;\n",
-    "pd=pm*sin(d);\n",
-    "pd=round(pd*10)/10;\n",
-    "print\"the power developed=MW\",pd\n",
-    "d=d*pi/180;\n",
-    "v=asin(cos(3.14-d))+31.9;\n",
-    "p=pm*sin(-v);\n",
-    "p=round(p);\n",
-    "pz=383-69.6;\n",
-    "print\"permissible sudden action loading without loss of transient stability with initial rotor angle 8degree = MW\",pz\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 44_8 pgno:897"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 21,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the clearing critical angle =(electrical degrees) 65.0838378975\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sin,cos,pi,asin,acos\n",
-    "p2=.4;\n",
-    "p3=1.3;\n",
-    "p1=1.8;\n",
-    "d1=asin(1./p1);\n",
-    "d1=round(d1*10)/10.;\n",
-    "d3=180-asin(1./p3);\n",
-    "k=d1-d3;\n",
-    "t=(p2*cos(d1));\n",
-    "p=(cos(d3));\n",
-    "y=cos(68.4642);\n",
-    "c=acos(y)*100;#the difference in result is due to erroneous calculation in textbook.\n",
-    "print\"the clearing critical angle =(electrical degrees)\",c\n",
-    "print\"the difference in result is due to erroneous calculation in textbook.\"\n"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_44_Power_system_Stability_1.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_44_Power_system_Stability_1.ipynb
deleted file mode 100755
index 836c8e51..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_44_Power_system_Stability_1.ipynb
+++ /dev/null
@@ -1,332 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 44 Power system Stability,Auto Reclosing Schemes ,Methods of Analysis and Improvement of Transient Stability"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 44_1 pgno:878"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 14,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the maximum 3 phase=MW 1889.28\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sqrt\n",
-    "v=115.;\n",
-    "x=7.;\n",
-    "v=v/sqrt(3);\n",
-    "pm=v**2/x;\n",
-    "ps=pm*v*v/x;\n",
-    "pm3=round(pm*100)/100;\n",
-    "pm3=pm3*3;\n",
-    "print\"the maximum 3 phase=MW\",pm3\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 44_2 pgno:878"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 15,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the maximum 3 phase=MW 826.5\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sqrt\n",
-    "x=complex(4,7);\n",
-    "v=115/sqrt(3);\n",
-    "pm=(v**2/sqrt((x.real**2)+(x.imag**2)))-(x.real*v**2/((x.real**2)+(x.imag**2)));\n",
-    "pm3=round(pm*100)/100;\n",
-    "pm3=3*pm3;\n",
-    "print\"the maximum 3 phase=MW\",pm3\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 44_3 pgno:881"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 16,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the steady state limit=p.u. 3.22561640727\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import pi,acos,atan,cos,sin\n",
-    "v=1;\n",
-    "p=.91;\n",
-    "y=acos(-.91)-180;\n",
-    "y=round(y*10)/10;\n",
-    "i=v*complex(cos(y*pi/180),sin(y*pi/180))\n",
-    "x=.37*complex(cos(pi/2),sin(pi/2))\n",
-    "e=v+(i*x);\n",
-    "#e=round(e*100)/100;\n",
-    "p=abs(e/x)*v+0.3;\n",
-    "print\"the steady state limit=p.u.\",p\n",
-    "#a=atand(imag(i),real(i))\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 44_4a pgno:887"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 17,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the value of angulr momentum M=MJs/ele.degrees\n",
-      "the Inertia Constant H=MJ/MVA 0.329 355.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "j=50e2;\n",
-    "r=100e6;\n",
-    "f=60;\n",
-    "p=2;\n",
-    "g=10;\n",
-    "n=120*f/p;\n",
-    "w=2*3.14*n/60;\n",
-    "ke=.5*j*w**2*100;\n",
-    "h=ke/r;\n",
-    "m=g*h/(180*f)\n",
-    "m=round(m*1000)/1000;\n",
-    "print\"the value of angulr momentum M=MJs/ele.degrees\\nthe Inertia Constant H=MJ/MVA\",m,round(h)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 44_5 pgno:891"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 18,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "stored energy=MJ 1600.0\n",
-      "\n",
-      "the angular acceleration= elec.degrees/sec^2 337.5\n"
-     ]
-    }
-   ],
-   "source": [
-    "r=200.;\n",
-    "c=8.;\n",
-    "e=c*r;\n",
-    "f=50.;\n",
-    "print\"stored energy=MJ\",e\n",
-    "ps=160e6;\n",
-    "pe=100e6;\n",
-    "p=ps-pe;\n",
-    "m=e*1e6/(180*f);\n",
-    "a=p/m;\n",
-    "print\"\\nthe angular acceleration= elec.degrees/sec^2\",a\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 44_6 pgno:891"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 19,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the angular momentum is MJ.s/elec.degree\tor\tMJs/rad 0.0185 1.06\n",
-      "\n",
-      "the angular acceleration =rad/sec^2 2.36\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import pi\n",
-    "ke=200e6;\n",
-    "r=50e6;\n",
-    "ps=25e6;\n",
-    "pe=22.5e6;\n",
-    "g=50;\n",
-    "f=60;\n",
-    "p=ps-pe;\n",
-    "h=ke/r;\n",
-    "m=g*h/(180*f);\n",
-    "m=round(m*10000)/10000;\n",
-    "n=m*180/(pi);\n",
-    "n=round(n*100)/100\n",
-    "print\"the angular momentum is MJ.s/elec.degree\\tor\\tMJs/rad\",m,n\n",
-    "a=p/n/1e6;\n",
-    "print\"\\nthe angular acceleration =rad/sec^2\",round(a,2)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 44_7 pgno:394"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 20,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the power developed=MW 494.7\n",
-      "permissible sudden action loading without loss of transient stability with initial rotor angle 8degree = MW 313.4\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import pi,sin,cos,asin\n",
-    "pm=500;\n",
-    "d=8;\n",
-    "pd=pm*sin(d);\n",
-    "pd=round(pd*10)/10;\n",
-    "print\"the power developed=MW\",pd\n",
-    "d=d*pi/180;\n",
-    "v=asin(cos(3.14-d))+31.9;\n",
-    "p=pm*sin(-v);\n",
-    "p=round(p);\n",
-    "pz=383-69.6;\n",
-    "print\"permissible sudden action loading without loss of transient stability with initial rotor angle 8degree = MW\",pz\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 44_8 pgno:897"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 21,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the clearing critical angle =(electrical degrees) 65.0838378975\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sin,cos,pi,asin,acos\n",
-    "p2=.4;\n",
-    "p3=1.3;\n",
-    "p1=1.8;\n",
-    "d1=asin(1./p1);\n",
-    "d1=round(d1*10)/10.;\n",
-    "d3=180-asin(1./p3);\n",
-    "k=d1-d3;\n",
-    "t=(p2*cos(d1));\n",
-    "p=(cos(d3));\n",
-    "y=cos(68.4642);\n",
-    "c=acos(y)*100;#the difference in result is due to erroneous calculation in textbook.\n",
-    "print\"the clearing critical angle =(electrical degrees)\",c\n",
-    "print\"the difference in result is due to erroneous calculation in textbook.\"\n"
-   ]
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_45_Load_Frquency_Control,Load_sheeding_and_Static_relay.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_45_Load_Frquency_Control,Load_sheeding_and_Static_relay.ipynb
deleted file mode 100755
index 031e8829..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_45_Load_Frquency_Control,Load_sheeding_and_Static_relay.ipynb
+++ /dev/null
@@ -1,282 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 45 Load Frquency Control,Load sheeding and Static relay"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 45_1 pgno:944"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 11,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the power factor=\n",
-      "the rating=kVA\n",
-      " the kVAr of system=kVA 0.753768844221 159.2 104.616633477\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sqrt\n",
-    "v=460;\n",
-    "i=200;\n",
-    "r=1.73*v*i/1e3;\n",
-    "r=round(r*10)/10;\n",
-    "p=120;\n",
-    "c=p/r;#the difference in result is due to erroneous calculation in textbook.\n",
-    "s=sqrt(1-(c**2))\n",
-    "rr=r*s;\n",
-    "print\"the power factor=\\nthe rating=kVA\\n the kVAr of system=kVA\",c,r,rr\n",
-    "print\"the difference in result is due to erroneous calculation in textbook.\"\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 45_2 pgno:944"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 12,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the power factor of the substation= 0.98\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sin,cos,acos,sqrt\n",
-    "r1=75;\n",
-    "c1=.8;\n",
-    "p1=r1*c1;\n",
-    "rr1=r1*(sin(acos(c1)));\n",
-    "r2=150;\n",
-    "c2=.8;\n",
-    "p2=r2*c2;\n",
-    "rr2=r2*(sin(acos(c2)));\n",
-    "r3=50;\n",
-    "c3=1;\n",
-    "p3=r3*c3;\n",
-    "rr3=r3*(sin(acos(c3)));\n",
-    "rr=-rr1+rr2+rr3;\n",
-    "p=p1+p2+p3;\n",
-    "r=sqrt(p**2+rr**2);\n",
-    "r=round(r)\n",
-    "j=p/r;\n",
-    "print\"the power factor of the substation=\",round(j,2)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 45_3 pgno:945"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 13,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the kVAr of capacitors = kVA 32.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sin,cos,acos,sqrt\n",
-    "c1=.8;\n",
-    "p1=120;\n",
-    "r1=p1/c1;\n",
-    "rr1=r1*(sin(acos(c1)));\n",
-    "c2=.9;\n",
-    "r2=p1/c2;\n",
-    "rr2=r2*(sin(acos(c2)));\n",
-    "rr2=round(rr2);\n",
-    "rr=rr1-rr2;\n",
-    "print\"the kVAr of capacitors = kVA\",rr\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 45_4 pgno:946"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 14,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the power factor is  0.9375\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "k=100.;\n",
-    "s=400.;\n",
-    "pf=1-((k/s)**2);\n",
-    "print\"the power factor is \",pf\n",
-    "print\"the difference in result is due to erroneous calculation in textbook.\"\n",
-    "\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 45_5 pgno:946"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 15,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the power factor is (lag) 0.97\n"
-     ]
-    }
-   ],
-   "source": [
-    "k=12.\n",
-    "m=72.;\n",
-    "pf=1-((k/m)**2);\n",
-    "print\"the power factor is (lag)\",round(pf,2)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 45_6 pgno:946"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 16,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the Power Factor of the combined sub-station= leading 0.965\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sin,cos,acos,sqrt,tan,atan\n",
-    "\n",
-    "n1=.89;\n",
-    "h1=150;\n",
-    "c1=.9;\n",
-    "h2=200;\n",
-    "n2=.9;\n",
-    "c2=.8;\n",
-    "h3=500;\n",
-    "n3=.93;\n",
-    "c3=.707;\n",
-    "p4=100;\n",
-    "p1=h1*.746/n1;\n",
-    "p2=h2*.746/n2;\n",
-    "p3=h3*.746/n3;\n",
-    "rr1=p1*(tan(acos(c1)));\n",
-    "rr2=p2*(tan(acos(c2)));\n",
-    "rr3=p3*(tan(acos(c3)));\n",
-    "rr4=0;\n",
-    "rr=rr1+rr2-rr3+rr4;\n",
-    "p=p1+p2+p3+p4;\n",
-    "c=rr/p;\n",
-    "j=cos(atan(c));\n",
-    "j=round(j*1000)/1000;\n",
-    "print\"the Power Factor of the combined sub-station= leading\",j\n",
-    "\n",
-    "\n"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_45_Load_Frquency_Control,Load_sheeding_and_Static_relay_1.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_45_Load_Frquency_Control,Load_sheeding_and_Static_relay_1.ipynb
deleted file mode 100755
index b5bf08a8..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_45_Load_Frquency_Control,Load_sheeding_and_Static_relay_1.ipynb
+++ /dev/null
@@ -1,264 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 45 Load Frquency Control,Load sheeding and Static relay"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 45_1 pgno:944"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 11,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the power factor=\n",
-      "the rating=kVA\n",
-      " the kVAr of system=kVA 0.753768844221 159.2 104.616633477\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sqrt\n",
-    "v=460;\n",
-    "i=200;\n",
-    "r=1.73*v*i/1e3;\n",
-    "r=round(r*10)/10;\n",
-    "p=120;\n",
-    "c=p/r;#the difference in result is due to erroneous calculation in textbook.\n",
-    "s=sqrt(1-(c**2))\n",
-    "rr=r*s;\n",
-    "print\"the power factor=\\nthe rating=kVA\\n the kVAr of system=kVA\",c,r,rr\n",
-    "print\"the difference in result is due to erroneous calculation in textbook.\"\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 45_2 pgno:944"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 12,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the power factor of the substation= 0.98\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sin,cos,acos,sqrt\n",
-    "r1=75;\n",
-    "c1=.8;\n",
-    "p1=r1*c1;\n",
-    "rr1=r1*(sin(acos(c1)));\n",
-    "r2=150;\n",
-    "c2=.8;\n",
-    "p2=r2*c2;\n",
-    "rr2=r2*(sin(acos(c2)));\n",
-    "r3=50;\n",
-    "c3=1;\n",
-    "p3=r3*c3;\n",
-    "rr3=r3*(sin(acos(c3)));\n",
-    "rr=-rr1+rr2+rr3;\n",
-    "p=p1+p2+p3;\n",
-    "r=sqrt(p**2+rr**2);\n",
-    "r=round(r)\n",
-    "j=p/r;\n",
-    "print\"the power factor of the substation=\",round(j,2)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 45_3 pgno:945"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 13,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the kVAr of capacitors = kVA 32.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sin,cos,acos,sqrt\n",
-    "c1=.8;\n",
-    "p1=120;\n",
-    "r1=p1/c1;\n",
-    "rr1=r1*(sin(acos(c1)));\n",
-    "c2=.9;\n",
-    "r2=p1/c2;\n",
-    "rr2=r2*(sin(acos(c2)));\n",
-    "rr2=round(rr2);\n",
-    "rr=rr1-rr2;\n",
-    "print\"the kVAr of capacitors = kVA\",rr\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 45_4 pgno:946"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 14,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the power factor is  0.9375\n",
-      "the difference in result is due to erroneous calculation in textbook.\n"
-     ]
-    }
-   ],
-   "source": [
-    "k=100.;\n",
-    "s=400.;\n",
-    "pf=1-((k/s)**2);\n",
-    "print\"the power factor is \",pf\n",
-    "print\"the difference in result is due to erroneous calculation in textbook.\"\n",
-    "\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 45_5 pgno:946"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 15,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the power factor is (lag) 0.97\n"
-     ]
-    }
-   ],
-   "source": [
-    "k=12.\n",
-    "m=72.;\n",
-    "pf=1-((k/m)**2);\n",
-    "print\"the power factor is (lag)\",round(pf,2)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 45_6 pgno:946"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 16,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the Power Factor of the combined sub-station= leading 0.965\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import sin,cos,acos,sqrt,tan,atan\n",
-    "\n",
-    "n1=.89;\n",
-    "h1=150;\n",
-    "c1=.9;\n",
-    "h2=200;\n",
-    "n2=.9;\n",
-    "c2=.8;\n",
-    "h3=500;\n",
-    "n3=.93;\n",
-    "c3=.707;\n",
-    "p4=100;\n",
-    "p1=h1*.746/n1;\n",
-    "p2=h2*.746/n2;\n",
-    "p3=h3*.746/n3;\n",
-    "rr1=p1*(tan(acos(c1)));\n",
-    "rr2=p2*(tan(acos(c2)));\n",
-    "rr3=p3*(tan(acos(c3)));\n",
-    "rr4=0;\n",
-    "rr=rr1+rr2-rr3+rr4;\n",
-    "p=p1+p2+p3+p4;\n",
-    "c=rr/p;\n",
-    "j=cos(atan(c));\n",
-    "j=round(j*1000)/1000;\n",
-    "print\"the Power Factor of the combined sub-station= leading\",j\n",
-    "\n",
-    "\n"
-   ]
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_46_Digital_computer_Aided_Protection_and_Automation.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_46_Digital_computer_Aided_Protection_and_Automation.ipynb
deleted file mode 100755
index 38554ee6..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_46_Digital_computer_Aided_Protection_and_Automation.ipynb
+++ /dev/null
@@ -1,205 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 46 Digital computer Aided Protection and Automation"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 46_1 pgno:1017"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 2,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "incremental cost(rs./MWhr)\tloading of unit 1(MW) \t loading of unit 2(MW)\ttotal generating power(MW)\n",
-      "\n",
-      "\t\t\t\t\t\t\t\t20 125 125 250\n"
-     ]
-    }
-   ],
-   "source": [
-    "#for low loads\n",
-    "p11=20;\n",
-    "p21=30;\n",
-    "t11=.1*p11+20;\n",
-    "t21=.12*p21+16;\n",
-    "#when load is further increased\n",
-    "t24=22;\n",
-    "p24=(t24-16)/.12;\n",
-    "t14=t24;\n",
-    "#upper limit 125MW\n",
-    "p25=125;\n",
-    "t15=1.12*p25+16;\n",
-    "p15=(t15-20)/.1;\n",
-    "n=7;\n",
-    "t21=19.6;\n",
-    "t22=20;\n",
-    "t23=21;\n",
-    "t24=22;\n",
-    "t25=31;\n",
-    "t26=32;\n",
-    "t27=32.5;\n",
-    "p15=110;\n",
-    "p2i=125;\n",
-    "p16=120;\n",
-    "p17=125;\n",
-    "p1i=125;\n",
-    "t2i=20;\n",
-    "for j in range(0,4):\n",
-    "        p1j=20;\n",
-    "\n",
-    "print\"incremental cost(rs./MWhr)\\tloading of unit 1(MW) \\t loading of unit 2(MW)\\ttotal generating power(MW)\"\n",
-    "for i in range(0,n):\n",
-    "    p2i1=(-16)/.12;\n",
-    "    if(21>=31):\n",
-    "        p2i=125;\n",
-    "\n",
-    "        \n",
-    "pti=p1i+p2i;\n",
-    "print\"\\n\\t\\t\\t\\t\\t\\t\\t\\t\",t2i,p1i,p2i,pti"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 46_2 pgno:1019"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 3,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "loading of unit 1 P1=MW\n",
-      "the loading of unit 2 P2=MW\n",
-      "incremental operating cost =Rs/MWhr 80.0 100.0 28.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "p=180;\n",
-    "p2=(20-16+(180*.1))/(.1+.12);\n",
-    "p1=p-p2;\n",
-    "t=.1*p1+20;\n",
-    "print\"loading of unit 1 P1=MW\\nthe loading of unit 2 P2=MW\\nincremental operating cost =Rs/MWhr\",p1,p2,t\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 46_3 pgno:1020"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 4,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "economic loading for unit 1=Rs/hr\n",
-      "economic loading for unit 2=Rs/hr\n",
-      "annual savings=Rs 284 250 4677840\n"
-     ]
-    }
-   ],
-   "source": [
-    "import scipy\n",
-    "from scipy import integrate\n",
-    "p11=80;\n",
-    "p12=90;\n",
-    "p21=100;\n",
-    "p22=90;\n",
-    "def fun1(x):\n",
-    "\ty=.1*x+20\n",
-    "\treturn y\n",
-    "\n",
-    "x=284#scipy.integrate.quad(fun1,p11,p12)\n",
-    "\n",
-    "def fun2(x):\n",
-    "\ty=.2*x+6\n",
-    "\treturn y\n",
-    "\n",
-    "y=250#scipy.integrate.quad(fun2,p22,p21)\n",
-    "\n",
-    "p=x+y;\n",
-    "aS=p*8760;\n",
-    "print\"economic loading for unit 1=Rs/hr\\neconomic loading for unit 2=Rs/hr\\nannual savings=Rs\",x,y,aS\n"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_46_Digital_computer_Aided_Protection_and_Automation_1.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_46_Digital_computer_Aided_Protection_and_Automation_1.ipynb
deleted file mode 100755
index 5edbc818..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_46_Digital_computer_Aided_Protection_and_Automation_1.ipynb
+++ /dev/null
@@ -1,178 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 46 Digital computer Aided Protection and Automation"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 46_1 pgno:1017"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 2,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "incremental cost(rs./MWhr)\tloading of unit 1(MW) \t loading of unit 2(MW)\ttotal generating power(MW)\n",
-      "\n",
-      "\t\t\t\t\t\t\t\t20 125 125 250\n"
-     ]
-    }
-   ],
-   "source": [
-    "#for low loads\n",
-    "p11=20;\n",
-    "p21=30;\n",
-    "t11=.1*p11+20;\n",
-    "t21=.12*p21+16;\n",
-    "#when load is further increased\n",
-    "t24=22;\n",
-    "p24=(t24-16)/.12;\n",
-    "t14=t24;\n",
-    "#upper limit 125MW\n",
-    "p25=125;\n",
-    "t15=1.12*p25+16;\n",
-    "p15=(t15-20)/.1;\n",
-    "n=7;\n",
-    "t21=19.6;\n",
-    "t22=20;\n",
-    "t23=21;\n",
-    "t24=22;\n",
-    "t25=31;\n",
-    "t26=32;\n",
-    "t27=32.5;\n",
-    "p15=110;\n",
-    "p2i=125;\n",
-    "p16=120;\n",
-    "p17=125;\n",
-    "p1i=125;\n",
-    "t2i=20;\n",
-    "for j in range(0,4):\n",
-    "        p1j=20;\n",
-    "\n",
-    "print\"incremental cost(rs./MWhr)\\tloading of unit 1(MW) \\t loading of unit 2(MW)\\ttotal generating power(MW)\"\n",
-    "for i in range(0,n):\n",
-    "    p2i1=(-16)/.12;\n",
-    "    if(21>=31):\n",
-    "        p2i=125;\n",
-    "\n",
-    "        \n",
-    "pti=p1i+p2i;\n",
-    "print\"\\n\\t\\t\\t\\t\\t\\t\\t\\t\",t2i,p1i,p2i,pti"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 46_2 pgno:1019"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 3,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "loading of unit 1 P1=MW\n",
-      "the loading of unit 2 P2=MW\n",
-      "incremental operating cost =Rs/MWhr 80.0 100.0 28.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "p=180;\n",
-    "p2=(20-16+(180*.1))/(.1+.12);\n",
-    "p1=p-p2;\n",
-    "t=.1*p1+20;\n",
-    "print\"loading of unit 1 P1=MW\\nthe loading of unit 2 P2=MW\\nincremental operating cost =Rs/MWhr\",p1,p2,t\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 46_3 pgno:1020"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 4,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "economic loading for unit 1=Rs/hr\n",
-      "economic loading for unit 2=Rs/hr\n",
-      "annual savings=Rs 284 250 4677840\n"
-     ]
-    }
-   ],
-   "source": [
-    "import scipy\n",
-    "from scipy import integrate\n",
-    "p11=80;\n",
-    "p12=90;\n",
-    "p21=100;\n",
-    "p22=90;\n",
-    "def fun1(x):\n",
-    "\ty=.1*x+20\n",
-    "\treturn y\n",
-    "\n",
-    "x=284#scipy.integrate.quad(fun1,p11,p12)\n",
-    "\n",
-    "def fun2(x):\n",
-    "\ty=.2*x+6\n",
-    "\treturn y\n",
-    "\n",
-    "y=250#scipy.integrate.quad(fun2,p22,p21)\n",
-    "\n",
-    "p=x+y;\n",
-    "aS=p*8760;\n",
-    "print\"economic loading for unit 1=Rs/hr\\neconomic loading for unit 2=Rs/hr\\nannual savings=Rs\",x,y,aS\n"
-   ]
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_57_Power_Flow_Calculations.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_57_Power_Flow_Calculations.ipynb
deleted file mode 100755
index 4a4bfa1a..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_57_Power_Flow_Calculations.ipynb
+++ /dev/null
@@ -1,507 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 57 Power Flow Calculations"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_1 pgno:1187"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 26,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the branch current I=/_A\n",
-      "the Branch Admittance=+()j mho 20.0 -0.927295218002 0.12 -0.16\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import atan\n",
-    "v=100;\n",
-    "z=complex(3,4)\n",
-    "i=v/z;\n",
-    "y=1/z;\n",
-    "ia=atan(i.imag/i.real);\n",
-    "print\"the branch current I=/_A\\nthe Branch Admittance=+()j mho\",abs(i),ia,y.real,y.imag\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_2 pgno:1198"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 27,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the impedence=mho 0.2\n"
-     ]
-    }
-   ],
-   "source": [
-    "z=complex(3,4)\n",
-    "y=1/z;\n",
-    "print\"the impedence=mho\",abs(y)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_4 pgno:1194"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 28,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "used value in iteration\titeration number\tresulting value of V2\n",
-      "(1+0j)\n",
-      "\t\t\t\t\t\t(0.962-0.05j)\n",
-      "(0.962-0.05j)\n",
-      "\t\t\t\t\t\t(0.957911-0.049787j)\n",
-      "(0.9527-0.497j)\n",
-      "\t\t\t\t\t\t(0.957732-0.05j)\n",
-      "(0.9577-0.05j)\n",
-      "\t\t\t\t\t\t(0.957713-0.049999j)\n"
-     ]
-    }
-   ],
-   "source": [
-    "v1=1;\n",
-    "z=complex(.05,.02);\n",
-    "s=complex(1,-.6);\n",
-    "c=.000005;\n",
-    "#v[2,1]=1;\n",
-    "print\"used value in iteration\\titeration number\\tresulting value of V2\"\n",
-    "import numpy\n",
-    "v1=numpy.array([complex(1,0), complex(0.962,-0.05), complex(0.9527,-0.497), complex(0.9577,-0.05), complex(0.9577,-0.049999)])\n",
-    "v2=numpy.array([complex(0.962000,(-0.050000)), complex(0.957911,(-0.049787)), complex(0.957732,(-0.050000)), complex(0.957713,(-0.049999)), complex(0.957712,(-0.050000))])\n",
-    "for i in range(0,4):\n",
-    "\tprint v1[i]\n",
-    "\tprint \"\\t\\t\\t\\t\\t\\t\",v2[i]"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_5 pgno:1197"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 29,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the power angle=/_ degrees 0.523598775598\n"
-     ]
-    }
-   ],
-   "source": [
-    "x=.05;\n",
-    "vs=1;\n",
-    "vr=1;\n",
-    "p=10;\n",
-    "from math import asin\n",
-    "d=asin(p*x);\n",
-    "print\"the power angle=/_ degrees\",d\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_6 pgno:1198"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 30,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "10.0 5.36\n"
-     ]
-    }
-   ],
-   "source": [
-    "x=.05;\n",
-    "vs=1.;\n",
-    "vr=1.;\n",
-    "p=10.;\n",
-    "from math import asin,cos\n",
-    "d=asin(p*x);\n",
-    "qs=(vs**2/x)-(vs*vr*cos(d)/x);\n",
-    "qs=round(qs*100)/100;\n",
-    "qR=(vs**2/x)-(vs*vr*cos(d)/x);\n",
-    "qR=round(qR*100)/100;\n",
-    "q=(qs+qR);\n",
-    "print p,q"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_7 pgno:1198"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 31,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "active power flow=pu -19.7606324819\n"
-     ]
-    }
-   ],
-   "source": [
-    "\n",
-    "x=.05;\n",
-    "d=30;\n",
-    "vs=1;\n",
-    "vr=1;\n",
-    "from math import sin\n",
-    "p=vs*vr*sin(d)/x;\n",
-    "print\"active power flow=pu\",p\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_8 pgno:1198"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 32,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "sending end voltage=/_V\n",
-      "the average reactive power flow=pu 0.965865415055 0.0621604788211 -0.66\n"
-     ]
-    }
-   ],
-   "source": [
-    "z=complex(0,.06)\n",
-    "i=complex(1,.6)\n",
-    "from math import atan\n",
-    "vr=1;\n",
-    "vs=vr+(i*z);\n",
-    "q=.5*((abs(vs))**2-(abs(vr))**2)/abs(z);\n",
-    "q=q-.1;\n",
-    "a=atan((vs.imag)/(vs.real))\n",
-    "print\"sending end voltage=/_V\\nthe average reactive power flow=pu\",abs(vs),a,round(q,2)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_9 pgno:1199"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 33,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the complex power=+jpu\n",
-      " the real power P=pu\n",
-      "the reactive powers=pu 1.078 0.5697\n"
-     ]
-    }
-   ],
-   "source": [
-    "\n",
-    "v=1;\n",
-    "from math import cos,sin,pi\n",
-    "i=1.188*complex(cos(-28.6*pi/180),sin(-28.6*pi/180));\n",
-    "s=v*complex(cos(-28.6*pi/180),-sin(-28.6*pi/180));\n",
-    "p=(s.real)+0.2;\n",
-    "q=((s.imag))+0.091;\n",
-    "print\"the complex power=+jpu\\n the real power P=pu\\nthe reactive powers=pu\",round(p,3),round(q,4)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_12 pgno:1208"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 34,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the voltage =+()jV 0.9738624 -0.0517056\n"
-     ]
-    }
-   ],
-   "source": [
-    "v21=1;\n",
-    "v22=complex(.983664,-.032316);\n",
-    "a=1.6;\n",
-    "v23=v21+a*(v22-v21);\n",
-    "print\"the voltage =+()jV\",(v23.real),(v23.imag)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_14 pgno:1215"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 35,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "power flow per pole=MW\n",
-      "bipolar line flow=MW\n",
-      "the line loss per pole in bipolat line=MW\n",
-      "bipolar line loss=MW\n",
-      "reactive power flow through DC link=MW 500.0 1000.0 20.0 40.0 0\n"
-     ]
-    }
-   ],
-   "source": [
-    "ud1=510.;\n",
-    "ud2=490.;\n",
-    "ud=(ud1+ud2)/2;\n",
-    "id=1;\n",
-    "p=ud*id;\n",
-    "b=2*p;\n",
-    "r=(ud1-ud2)/id;\n",
-    "pl=r;\n",
-    "pbl=2*pl;\n",
-    "pdr=ud1;\n",
-    "pdi=ud2;\n",
-    "pz=pdr-pdi;\n",
-    "print\"power flow per pole=MW\\nbipolar line flow=MW\\nthe line loss per pole in bipolat line=MW\\nbipolar line loss=MW\\nreactive power flow through DC link=MW\",p,b,pl,pbl,0\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_15 pgno:1216"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 36,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the sending end power=MW\n",
-      "power in middle=MW\n",
-      "DC sending end voltage=kV\n",
-      "recieving end DC voltage=kV\n",
-      "DC voltage in middle of line=kV\n",
-      "Line Resistance =ohm 1060.0 1030.0 1060.0 530.0 515.0 30.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "pdi=1000.;\n",
-    "pdl=60.;\n",
-    "ud=1.;\n",
-    "pdr=pdi+pdl;\n",
-    "p=(pdr+pdi)/2;\n",
-    "id=pdi/ud;\n",
-    "pdc=pdr*1e3/id;\n",
-    "rec=pdc/2;\n",
-    "vdc=(rec+(pdi/2))/2;\n",
-    "udr=rec;\n",
-    "udi=pdi/2;\n",
-    "r=(udr-udi)*1e3/id;\n",
-    "print\"the sending end power=MW\\npower in middle=MW\\nDC sending end voltage=kV\\nrecieving end DC voltage=kV\\nDC voltage in middle of line=kV\\nLine Resistance =ohm\",pdr,p,pdc,rec,vdc,r"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_16 pgno:1219"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 37,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "power flow through 4th AC line=MW 1000.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "pg=6000.;\n",
-    "pdc=1000.;\n",
-    "pac=pg-(2*pdc);\n",
-    "pac1=1000.;\n",
-    "pac2=1000.;\n",
-    "pac3=1000.;\n",
-    "pac4=pac-pac1-pac2-pac3;\n",
-    "print\"power flow through 4th AC line=MW\",pac4\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_17 pgno:1219"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 38,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "power flow through AC line=MW 500.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "pg=6000.;\n",
-    "pdc=4000.;\n",
-    "pac=pg-pdc;\n",
-    "pow=pac/4;\n",
-    "print\"power flow through AC line=MW\",pow\n",
-    "\n"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_57_Power_Flow_Calculations_1.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_57_Power_Flow_Calculations_1.ipynb
deleted file mode 100755
index 567b5d06..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_57_Power_Flow_Calculations_1.ipynb
+++ /dev/null
@@ -1,489 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 57 Power Flow Calculations"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_1 pgno:1187"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 26,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the branch current I=/_A\n",
-      "the Branch Admittance=+()j mho 20.0 -0.927295218002 0.12 -0.16\n"
-     ]
-    }
-   ],
-   "source": [
-    "from math import atan\n",
-    "v=100;\n",
-    "z=complex(3,4)\n",
-    "i=v/z;\n",
-    "y=1/z;\n",
-    "ia=atan(i.imag/i.real);\n",
-    "print\"the branch current I=/_A\\nthe Branch Admittance=+()j mho\",abs(i),ia,y.real,y.imag\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_2 pgno:1198"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 27,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the impedence=mho 0.2\n"
-     ]
-    }
-   ],
-   "source": [
-    "z=complex(3,4)\n",
-    "y=1/z;\n",
-    "print\"the impedence=mho\",abs(y)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_4 pgno:1194"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 28,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "used value in iteration\titeration number\tresulting value of V2\n",
-      "(1+0j)\n",
-      "\t\t\t\t\t\t(0.962-0.05j)\n",
-      "(0.962-0.05j)\n",
-      "\t\t\t\t\t\t(0.957911-0.049787j)\n",
-      "(0.9527-0.497j)\n",
-      "\t\t\t\t\t\t(0.957732-0.05j)\n",
-      "(0.9577-0.05j)\n",
-      "\t\t\t\t\t\t(0.957713-0.049999j)\n"
-     ]
-    }
-   ],
-   "source": [
-    "v1=1;\n",
-    "z=complex(.05,.02);\n",
-    "s=complex(1,-.6);\n",
-    "c=.000005;\n",
-    "#v[2,1]=1;\n",
-    "print\"used value in iteration\\titeration number\\tresulting value of V2\"\n",
-    "import numpy\n",
-    "v1=numpy.array([complex(1,0), complex(0.962,-0.05), complex(0.9527,-0.497), complex(0.9577,-0.05), complex(0.9577,-0.049999)])\n",
-    "v2=numpy.array([complex(0.962000,(-0.050000)), complex(0.957911,(-0.049787)), complex(0.957732,(-0.050000)), complex(0.957713,(-0.049999)), complex(0.957712,(-0.050000))])\n",
-    "for i in range(0,4):\n",
-    "\tprint v1[i]\n",
-    "\tprint \"\\t\\t\\t\\t\\t\\t\",v2[i]"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_5 pgno:1197"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 29,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the power angle=/_ degrees 0.523598775598\n"
-     ]
-    }
-   ],
-   "source": [
-    "x=.05;\n",
-    "vs=1;\n",
-    "vr=1;\n",
-    "p=10;\n",
-    "from math import asin\n",
-    "d=asin(p*x);\n",
-    "print\"the power angle=/_ degrees\",d\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_6 pgno:1198"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 30,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "10.0 5.36\n"
-     ]
-    }
-   ],
-   "source": [
-    "x=.05;\n",
-    "vs=1.;\n",
-    "vr=1.;\n",
-    "p=10.;\n",
-    "from math import asin,cos\n",
-    "d=asin(p*x);\n",
-    "qs=(vs**2/x)-(vs*vr*cos(d)/x);\n",
-    "qs=round(qs*100)/100;\n",
-    "qR=(vs**2/x)-(vs*vr*cos(d)/x);\n",
-    "qR=round(qR*100)/100;\n",
-    "q=(qs+qR);\n",
-    "print p,q"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_7 pgno:1198"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 31,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "active power flow=pu -19.7606324819\n"
-     ]
-    }
-   ],
-   "source": [
-    "\n",
-    "x=.05;\n",
-    "d=30;\n",
-    "vs=1;\n",
-    "vr=1;\n",
-    "from math import sin\n",
-    "p=vs*vr*sin(d)/x;\n",
-    "print\"active power flow=pu\",p\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_8 pgno:1198"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 32,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "sending end voltage=/_V\n",
-      "the average reactive power flow=pu 0.965865415055 0.0621604788211 -0.66\n"
-     ]
-    }
-   ],
-   "source": [
-    "z=complex(0,.06)\n",
-    "i=complex(1,.6)\n",
-    "from math import atan\n",
-    "vr=1;\n",
-    "vs=vr+(i*z);\n",
-    "q=.5*((abs(vs))**2-(abs(vr))**2)/abs(z);\n",
-    "q=q-.1;\n",
-    "a=atan((vs.imag)/(vs.real))\n",
-    "print\"sending end voltage=/_V\\nthe average reactive power flow=pu\",abs(vs),a,round(q,2)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_9 pgno:1199"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 33,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the complex power=+jpu\n",
-      " the real power P=pu\n",
-      "the reactive powers=pu 1.078 0.5697\n"
-     ]
-    }
-   ],
-   "source": [
-    "\n",
-    "v=1;\n",
-    "from math import cos,sin,pi\n",
-    "i=1.188*complex(cos(-28.6*pi/180),sin(-28.6*pi/180));\n",
-    "s=v*complex(cos(-28.6*pi/180),-sin(-28.6*pi/180));\n",
-    "p=(s.real)+0.2;\n",
-    "q=((s.imag))+0.091;\n",
-    "print\"the complex power=+jpu\\n the real power P=pu\\nthe reactive powers=pu\",round(p,3),round(q,4)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_12 pgno:1208"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 34,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the voltage =+()jV 0.9738624 -0.0517056\n"
-     ]
-    }
-   ],
-   "source": [
-    "v21=1;\n",
-    "v22=complex(.983664,-.032316);\n",
-    "a=1.6;\n",
-    "v23=v21+a*(v22-v21);\n",
-    "print\"the voltage =+()jV\",(v23.real),(v23.imag)\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_14 pgno:1215"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 35,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "power flow per pole=MW\n",
-      "bipolar line flow=MW\n",
-      "the line loss per pole in bipolat line=MW\n",
-      "bipolar line loss=MW\n",
-      "reactive power flow through DC link=MW 500.0 1000.0 20.0 40.0 0\n"
-     ]
-    }
-   ],
-   "source": [
-    "ud1=510.;\n",
-    "ud2=490.;\n",
-    "ud=(ud1+ud2)/2;\n",
-    "id=1;\n",
-    "p=ud*id;\n",
-    "b=2*p;\n",
-    "r=(ud1-ud2)/id;\n",
-    "pl=r;\n",
-    "pbl=2*pl;\n",
-    "pdr=ud1;\n",
-    "pdi=ud2;\n",
-    "pz=pdr-pdi;\n",
-    "print\"power flow per pole=MW\\nbipolar line flow=MW\\nthe line loss per pole in bipolat line=MW\\nbipolar line loss=MW\\nreactive power flow through DC link=MW\",p,b,pl,pbl,0\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_15 pgno:1216"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 36,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the sending end power=MW\n",
-      "power in middle=MW\n",
-      "DC sending end voltage=kV\n",
-      "recieving end DC voltage=kV\n",
-      "DC voltage in middle of line=kV\n",
-      "Line Resistance =ohm 1060.0 1030.0 1060.0 530.0 515.0 30.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "pdi=1000.;\n",
-    "pdl=60.;\n",
-    "ud=1.;\n",
-    "pdr=pdi+pdl;\n",
-    "p=(pdr+pdi)/2;\n",
-    "id=pdi/ud;\n",
-    "pdc=pdr*1e3/id;\n",
-    "rec=pdc/2;\n",
-    "vdc=(rec+(pdi/2))/2;\n",
-    "udr=rec;\n",
-    "udi=pdi/2;\n",
-    "r=(udr-udi)*1e3/id;\n",
-    "print\"the sending end power=MW\\npower in middle=MW\\nDC sending end voltage=kV\\nrecieving end DC voltage=kV\\nDC voltage in middle of line=kV\\nLine Resistance =ohm\",pdr,p,pdc,rec,vdc,r"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_16 pgno:1219"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 37,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "power flow through 4th AC line=MW 1000.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "pg=6000.;\n",
-    "pdc=1000.;\n",
-    "pac=pg-(2*pdc);\n",
-    "pac1=1000.;\n",
-    "pac2=1000.;\n",
-    "pac3=1000.;\n",
-    "pac4=pac-pac1-pac2-pac3;\n",
-    "print\"power flow through 4th AC line=MW\",pac4\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 57_17 pgno:1219"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 38,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "power flow through AC line=MW 500.0\n"
-     ]
-    }
-   ],
-   "source": [
-    "pg=6000.;\n",
-    "pdc=4000.;\n",
-    "pac=pg-pdc;\n",
-    "pow=pac/4;\n",
-    "print\"power flow through AC line=MW\",pow\n",
-    "\n"
-   ]
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_58_Applications_of_Switchgear.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_58_Applications_of_Switchgear.ipynb
deleted file mode 100755
index 80701a42..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_58_Applications_of_Switchgear.ipynb
+++ /dev/null
@@ -1,74 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 58 Applications of Switchgear"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 58_1 pgno:159"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 1,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the overcurrent factor= 12.5\n"
-     ]
-    }
-   ],
-   "source": [
-    "g=15.;\n",
-    "p=10.;\n",
-    "o=8.;\n",
-    "d=1.;\n",
-    "c=3.;\n",
-    "y=o+d+c;\n",
-    "oc=g*p/y;\n",
-    "print\"the overcurrent factor=\",oc\n"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
diff --git a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_58_Applications_of_Switchgear_1.ipynb b/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_58_Applications_of_Switchgear_1.ipynb
deleted file mode 100755
index d1f2d4d1..00000000
--- a/Switchgear_Protection_And_Power_Systems_by_S._S._Rao/Chapter_58_Applications_of_Switchgear_1.ipynb
+++ /dev/null
@@ -1,65 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Chapter 58 Applications of Switchgear"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Example 58_1 pgno:159"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 1,
-   "metadata": {
-    "collapsed": false
-   },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "the overcurrent factor= 12.5\n"
-     ]
-    }
-   ],
-   "source": [
-    "g=15.;\n",
-    "p=10.;\n",
-    "o=8.;\n",
-    "d=1.;\n",
-    "c=3.;\n",
-    "y=o+d+c;\n",
-    "oc=g*p/y;\n",
-    "print\"the overcurrent factor=\",oc\n"
-   ]
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 2",
-   "language": "python",
-   "name": "python2"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 2
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython2",
-   "version": "2.7.9"
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 0
-}
author	kinitrupti	2017-05-12 18:40:35 +0530
committer	kinitrupti	2017-05-12 18:40:35 +0530
commit	d36fc3b8f88cc3108ffff6151e376b619b9abb01 (patch)
tree	9806b0d68a708d2cfc4efc8ae3751423c56b7721 /Switchgear_Protection_And_Power_Systems_by_S._S._Rao
parent	1b1bb67e9ea912be5c8591523c8b328766e3680f (diff)
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