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Diffstat (limited to 'Power_Electronics/Chapter5_4.ipynb')
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diff --git a/Power_Electronics/Chapter5_4.ipynb b/Power_Electronics/Chapter5_4.ipynb new file mode 100755 index 00000000..1d261f20 --- /dev/null +++ b/Power_Electronics/Chapter5_4.ipynb @@ -0,0 +1,511 @@ +{
+ "metadata": {
+ "name": ""
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+ {
+ "cells": [
+ {
+ "cell_type": "heading",
+ "level": 1,
+ "metadata": {},
+ "source": [
+ "Chapter 05 : Thyristor Commutation Techniques"
+ ]
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 5.1, Page No 252"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "import math\n",
+ "#initialisation of variables\n",
+ "L=5.0*10**-3 #mH\n",
+ "C=20.0*10**-6 #\u00b5F\n",
+ "V_s=200 #V\n",
+ "\n",
+ "#Calculations\n",
+ "w_o=math.sqrt(1/(L*C)) #rad/s\n",
+ "t_o=math.pi/w_o #ms\n",
+ "\n",
+ "#Results\n",
+ "print('conduction time of thyristor = %.2f ms' %(t_o*1000))\n",
+ "print('voltage across thyristor=%.0f V' %V_s)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "conduction time of thyristor = 0.99 ms\n",
+ "voltage across thyristor=200 V\n"
+ ]
+ }
+ ],
+ "prompt_number": 12
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 5.2, Page No 255"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "import math\n",
+ "\n",
+ "#initialisation of variables\n",
+ "C=20.0*10**-6 #\u00b5F\n",
+ "L=5.0*10**-6 #\u00b5H\n",
+ "V_s=230.0 #V\n",
+ "\n",
+ "#Calculations\n",
+ "I_p=V_s*math.sqrt(C/L) #A\n",
+ "w_o=math.sqrt(1/(L*C)) #rad/sec\n",
+ "t_o=math.pi/w_o #\u00b5S\n",
+ "I_o=300 \n",
+ "a = math.degrees(math.asin(I_o/(2*V_s))) \n",
+ "V_ab = V_s*math.cos(math.radians(a)) #V \n",
+ "t_c=C*V_ab/I_o #\u00b5s\n",
+ "\n",
+ "#Calculations\n",
+ "print(\"conduction time of auxillery thyristor=%.2f us\" %(t_o*10**6))\n",
+ "print(\"voltage across main thyristor=%.2f V\" %V_ab)\n",
+ "print(\"ckt turn off time=%.2f us\" %(t_c*10**6))\n"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "conduction time of auxillery thyristor=31.42 us\n",
+ "voltage across main thyristor=174.36 V\n",
+ "ckt turn off time=11.62 us\n"
+ ]
+ }
+ ],
+ "prompt_number": 13
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 5.3 Page No 258"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "import math\n",
+ "\n",
+ "#initialisation of variables\n",
+ "V_s=200.0 #V\n",
+ "R1=10.0 #\u2126\n",
+ "R2=100.0 #\u2126\n",
+ "C=0 # value of capacitor\n",
+ "\n",
+ "#Calculations\n",
+ "I1=V_s*(1/R1+2/R2) #A\n",
+ "I2=V_s*(2/R1+1/R2) #A\n",
+ "t_c1=40*10**-6\n",
+ "fos=2 #factor of safety\n",
+ "C1=t_c1*fos/(R1*math.log(2))\n",
+ "C2=t_c1*fos/(R2*math.log(2))\n",
+ "if C1 > C2 :\n",
+ " C = C1*10**6\n",
+ "else :\n",
+ " C = C2*10**6\n",
+ "\n",
+ "\n",
+ "#Results\n",
+ "print(\"peak value of current through SCR1=%.2f A\" %I1); \n",
+ "print(\"Peak value of current through SCR2=%.2f A\" %I2);\n",
+ "print(\"Value of capacitor=%.2f uF\" %C);"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "peak value of current through SCR1=24.00 A\n",
+ "Peak value of current through SCR2=42.00 A\n",
+ "Value of capacitor=11.54 uF\n"
+ ]
+ }
+ ],
+ "prompt_number": 14
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 5.4, Page No 260"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "import math\n",
+ "#initialisation of variables\n",
+ "V_s=230.0 #V\n",
+ "L=20*10**-6 #\u00b5H\n",
+ "C=40*10**-6 #\u00b5F\n",
+ "I_o=120.0 #A\n",
+ "\n",
+ "#Calculations\n",
+ "I_p=V_s*math.sqrt(C/L) #A\n",
+ "t_c=C*V_s/I_o #\u00b5s\n",
+ "w_o=math.sqrt(1/(L*C)) \n",
+ "t_c1=math.pi/(2*w_o) #\u00b5s\n",
+ "\n",
+ "#Results\n",
+ "print(\"current through main thyristor=%.2f A\" %(I_o+I_p))\n",
+ "print(\"Current through auxillery thyristor=%.2f A\" %I_o)\n",
+ "print(\"Circuit turn off time for main thyristor=%.2f us\" %(t_c*10**6))\n",
+ "print(\"Circuit turn off time for auxillery thyristor=%.2f us\" %(t_c1*10**6))"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "current through main thyristor=445.27 A\n",
+ "Current through auxillery thyristor=120.00 A\n",
+ "Circuit turn off time for main thyristor=76.67 us\n",
+ "Circuit turn off time for auxillery thyristor=44.43 us\n"
+ ]
+ }
+ ],
+ "prompt_number": 15
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 5.5 Page No 263"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "import math\n",
+ "#initialisation of variables\n",
+ "C_j=25*10**-12 #pF\n",
+ "I_c=5*10**-3 #charging current\n",
+ "V_s=200.0 #V\n",
+ "R=50.0 #\u2126\n",
+ "\n",
+ "#Calculations\n",
+ "C=(C_j*V_s)/(I_c*R)\n",
+ "\n",
+ "\n",
+ "#RESULTS\n",
+ "print(\"Value of C=%.2f \u00b5F\" %(C*10**6))"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "Value of C=0.02 \u00b5F\n"
+ ]
+ }
+ ],
+ "prompt_number": 16
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 5.6 Page No 263"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "import math\n",
+ "\n",
+ "#initialisation of variables\n",
+ "V_s=200.0 #V\n",
+ "R=5.0 #\u2126\n",
+ "\n",
+ "#Calculations\n",
+ "C=10.0*10**-6\n",
+ "#for turn off V_s*(1-2*exp(-t/(R*C)))=0, so after solving\n",
+ "t_c=R*C*math.log(2.0)\n",
+ "\n",
+ "#Results\n",
+ "print(\"circuit turn off time=%.2f us\" %(t_c*10**6))"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "circuit turn off time=34.66 us\n"
+ ]
+ }
+ ],
+ "prompt_number": 17
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 5.7, Page No 264 "
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "import math\n",
+ "#initialisation of variables\n",
+ "R=1.0 #\u2126\n",
+ "L=20*10**-6 #\u00b5H\n",
+ "C=40*10**-6 #\u00b5F\n",
+ "\n",
+ "#Calculations\n",
+ "w_r=math.sqrt((1/(L*C))-(R/(2*L))**2)\n",
+ "t_1=math.pi/w_r\n",
+ "\n",
+ "#Results\n",
+ "print(\"conduction time of thyristor=%.3f us\" %(t_1*10**6))\n"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "conduction time of thyristor=125.664 us\n"
+ ]
+ }
+ ],
+ "prompt_number": 18
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 5.8 Page No 265"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "import math \n",
+ "\n",
+ "#initialisation of variables\n",
+ "dv=400*10.0**-6 #dv=dv_T/dt(V/s)\n",
+ "V_s=200.0 #v\n",
+ "R=20.0 #\u2126\n",
+ "\n",
+ "#Calculations\n",
+ "C=V_s/(R*dv) \n",
+ "C_j=.025*10**-12\n",
+ "C_s=C-C_j\n",
+ "I_T=40;\n",
+ "R_s=1/((I_T/V_s)-(1/R)) \n",
+ "#value of R_s in book is wrongly calculated\n",
+ "\n",
+ "#Results\n",
+ "print(\"R_s=%.2f ohm\" %R_s)\n",
+ "print(\"C_s=%.3f uF\" %(C_s/10**6))\n"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "R_s=6.67 ohm\n",
+ "C_s=0.025 uF\n"
+ ]
+ }
+ ],
+ "prompt_number": 19
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 5.9 Page No 265"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "import math\n",
+ "#initialisation of variables\n",
+ "V_s=200.0 #V\n",
+ "C=20.0*10**-6 #\u00b5H \n",
+ "L=0.2*10**-3 #\u00b5F\n",
+ "i_c=10.0\n",
+ "\n",
+ "#Calculations\n",
+ "i=V_s*math.sqrt(C/L)\n",
+ "w_o=1.0/math.sqrt(L*C)\n",
+ "t_1 = (1/w_o)*math.degrees(math.asin(i_c/i))\n",
+ "t_o=math.pi/w_o\n",
+ "t_c=t_o-2*t_1 \n",
+ "\n",
+ "#Results\n",
+ "print(\"reqd time=%.2f us\" %(t_1*10**6))\n",
+ "print(\"ckt turn off time=%.2f us\" %(t_c*10**6))\n",
+ "print(\"ckt turn off time=%.5f us\" %t_1)\n",
+ "#solution in book wrong, as wrong values are selected while filling the formuleas"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "reqd time=575.37 us\n",
+ "ckt turn off time=-952.05 us\n",
+ "ckt turn off time=0.00058 us\n"
+ ]
+ }
+ ],
+ "prompt_number": 20
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 5.11 Page No 268 "
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "import math\n",
+ "\n",
+ "#initialisation of variables\n",
+ "L=1.0 #\u00b5H\n",
+ "R=50.0 #\u2126\n",
+ "V_s=200.0 #V\n",
+ "t=0.01 #sec\n",
+ "Vd=0.7\n",
+ "\n",
+ "#Calculations\n",
+ "tau=L/R\n",
+ "i=(V_s/R)*(1-math.exp(-t/tau))\n",
+ "t=8*10**-3\n",
+ "i1=i-t*Vd \n",
+ "\n",
+ "\n",
+ "#Results\n",
+ "print(\"current through L = %.2f A\" %i1)\n",
+ "i_R=0 #current in R at t=.008s\n",
+ "print(\"Current through R = %.2f A\" %i_R)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "current through L = 1.57 A\n",
+ "Current through R = 0.00 A\n"
+ ]
+ }
+ ],
+ "prompt_number": 21
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 5.12, Page No 269"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "import math\n",
+ "\n",
+ "#initialisation of variables\n",
+ "\n",
+ "#initialisation of variables\n",
+ "L=1.0 #H\n",
+ "R=50.0 #ohm\n",
+ "V_s=200.0 #V\n",
+ "\n",
+ "#Calculations\n",
+ "tau=L/R\n",
+ "t=0.01 #s\n",
+ "i=(V_s/R)*(1-math.exp(-t/tau))\n",
+ "C=1*10**-6 #F\n",
+ "V_c=math.sqrt(L/C)*i\n",
+ "\n",
+ "#Results\n",
+ "print(\"current in R,L=%.2f A\" %i)\n",
+ "print(\"voltage across C=%.2f kV\" %(V_c/1000))"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "current in R,L=1.57 A\n",
+ "voltage across C=1.57 kV\n"
+ ]
+ }
+ ],
+ "prompt_number": 22
+ }
+ ],
+ "metadata": {}
+ }
+ ]
+}
\ No newline at end of file |