{
 "metadata": {
  "name": ""
 },
 "nbformat": 3,
 "nbformat_minor": 0,
 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Chapter 02 : Capacitance Of Transmission Lines"
     ]
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.1, Page No 75"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import math\n",
      "#initialisation of variables\n",
      "D = 20.0 #in ft\n",
      "f = 60.0 #in Hz\n",
      "\n",
      "#From Table A.1 and A.3\n",
      "d = 0.642 \t\t\t#in inches\n",
      "X_a = 0.1074e6 \t\t#in ohm-mi\n",
      "X_d = 0.0889e6 \t\t#in ohm-mi\n",
      "\n",
      "#finding radius\n",
      "r = d/(2*12) \t\t#divided by 12 convert in to ft\n",
      "\n",
      "#Calculations\n",
      "print('Calculations using conductor spacing and radius')\n",
      "X_c = 1.779 * math.log(D/r)/f\n",
      "B_c = 1 / X_c\n",
      "print(\" Capactive reatance = %.4fe6 ohm mi to neutral \" %X_c)\n",
      "print(\" Capactive susceptance = %.4fe-6 mho/mi to neutral \" %B_c)\n",
      "\n",
      "#calculations using capacitive reactance at 1-ft spacing and spacing factor\n",
      "print('Calculations using capacitive reactance at 1-ft spacing and spacing factor')\n",
      "X_c1 = X_a + X_d\n",
      "print(\" Capactive reatance = %.4fe6 ohm mi per conductor \" %(X_c1/10**6))\n",
      "X_c11 = 2 * X_c1\n",
      "B_c1 = 1 / X_c11\n",
      "\n",
      "#Results\n",
      "print(\" Line-to-line capactive reatance = %.4fe6 ohm mi \" %(X_c11/10**6))\n",
      "print(\" Line-to-line capactive susceptance = %.4fe-6 mho mi \" %(B_c1*10**6))"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Calculations using conductor spacing and radius\n",
        " Capactive reatance = 0.1962e6 ohm mi to neutral \n",
        " Capactive susceptance = 5.0970e-6 mho/mi to neutral \n",
        "Calculations using capacitive reactance at 1-ft spacing and spacing factor\n",
        " Capactive reatance = 0.1963e6 ohm mi per conductor \n",
        " Line-to-line capactive reatance = 0.3926e6 ohm mi \n",
        " Line-to-line capactive susceptance = 2.5471e-6 mho mi \n"
       ]
      }
     ],
     "prompt_number": 14
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.2, Page No 80"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import math\n",
      "#initialisation of variables\n",
      "D_12 = 20.0\t\t\t#in ft\n",
      "D_23 = D_12\n",
      "D_31 = 38.0\t\t\t#in ft\n",
      "f = 60.0\t\t\t#in Hz\n",
      "V = 220e3\t\t\t#in volts\n",
      "l = 175\t\t\t\t#in mi\n",
      "k = 8.85e-12\t\t#permittivity in F/m\n",
      "#From tables A.1 and A.3\n",
      "d = 1.108#in inches\n",
      "X_a1 = 0.0912e6#in ohm mi\n",
      "X_d1 = 0.0952e6#in ohm mi\n",
      "\n",
      "#Calculations\n",
      "r = d / ( 2 * 12)#division by 12 to convert in to ft\n",
      "D_eq = (D_12*D_23*D_31)**(1.0/3)\n",
      "C_n = (2*math.pi*k)/math.log(D_eq/r)\n",
      "X_c = 1.0/(2*math.pi*f*C_n*1609)\t\t#division by 1609 to convert to ohm mi\n",
      "\n",
      "print(\" Capacitance = %.4fe-12 F/m \" %(C_n*1e12))\n",
      "print(\" Capacitive reactance = %.4fe6 ohm mi \" %(X_c/1e6))\n",
      "\n",
      "#Calculations From tables\n",
      "X_c1 = X_a1 + X_d1\n",
      "print('Using capacitive reactance at 1-ft spacing and spacing factor')\n",
      "print(\" Capacitive reactance = %.4fe6 ohm mi \" %(X_c1/1e6))\n",
      "X_c_l = X_c1/l\t\t\t#Capacitive reactance for 175mi\n",
      "I_chg = 2*math.pi*f*V*C_n*1609/math.sqrt(3.0)\n",
      "I_chg_l = I_chg * l\n",
      "Q =math.sqrt(3)*V*I_chg_l\n",
      "\n",
      "\n",
      "#Results\n",
      "print('For a lenght of 175mi')\n",
      "print(\" Capacitive reactance = %.4f ohm to neutral \" %X_c_l)\n",
      "print(\" Charging current per mile = %.3f A/mi \" %I_chg)\n",
      "print('For a lenght of 175mi')\n",
      "print(\" Charging current = %.0f A \" %I_chg_l)\n",
      "print(\" Total charging megavolt-amperes = %.1f Mvar \" %(Q/1e6))\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " Capacitance = 8.8472e-12 F/m \n",
        " Capacitive reactance = 0.1863e6 ohm mi \n",
        "Using capacitive reactance at 1-ft spacing and spacing factor\n",
        " Capacitive reactance = 0.1864e6 ohm mi \n",
        "For a lenght of 175mi\n",
        " Capacitive reactance = 1065.1429 ohm to neutral \n",
        " Charging current per mile = 0.682 A/mi \n",
        "For a lenght of 175mi\n",
        " Charging current = 119 A \n",
        " Total charging megavolt-amperes = 45.5 Mvar \n"
       ]
      }
     ],
     "prompt_number": 15
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.3, Page No 85"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import math\n",
      "#initialisation of variables\n",
      "d = 0.45   #in m\n",
      "k = 8.85e-12  #in F/m\n",
      "D_ab = 8  #in m\n",
      "D_bc = D_ab\n",
      "D_ca = 16   #in m\n",
      "f = 60  #in Hz\n",
      "\n",
      "#From tables\n",
      "D = 1.382   #in inches\n",
      "\n",
      "#Calculations\n",
      "r = D*0.3048/(2.0*12)  #divison by 12 to convert in to ft\n",
      "                           #multiplication by 0.3048 to convert ft to m\n",
      "D_b_sC = math.sqrt( r * d)\n",
      "D_eq = (D_ab * D_bc * D_ca)**(1/3)\n",
      "C_m = 2* math.pi*k/math.log(D_eq / D_b_sC)\n",
      "X_c = 1e-3/(2*math.pi*f*C_m)  #1e-3     #to convert m to km\n",
      "\n",
      "#Results\n",
      "print(\" Capacitance = %.3fe-12 F/m \" %(C_m * 1e12))\n",
      "print(\" Capacitive reactance = %.4fe6 ohm km per phase to neutral\" %(X_c/1e6))"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " Capacitance = 22.972e-12 F/m \n",
        " Capacitive reactance = 0.1155e6 ohm km per phase to neutral\n"
       ]
      }
     ],
     "prompt_number": 16
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.4 Page No 85"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import math\n",
      "#initialisation of variables\n",
      "f = 60.0\t\t#in Hz\n",
      "k = 8.85e-12\t#in F/m\n",
      "D_eq = 16.1\t\t#in ft\n",
      "D_a_a1 = 26.9\n",
      "D_b_b1 = 21.0\n",
      "D_c_c1 = D_a_a1 #in ft\n",
      "\n",
      "#From Table A.1\n",
      "d = 0.680#in inches\n",
      "\n",
      "#calculations\n",
      "r = d /(2*12)\n",
      "D_p_sC = (math.sqrt(D_a_a1 * r) * math.sqrt(D_b_b1 * r) * math.sqrt(D_c_c1 * r))**(1.0/3)\n",
      "C_n = 2 * math.pi * k / math.log(D_eq / D_p_sC)\n",
      "B_c = 2 * math.pi * f * C_n * 1609.0\t#1609 to convert from m to mi\n",
      "\n",
      "#Results\n",
      "print(\"printprint Capacitance = %.3fe-12 F/m printprint\" %(C_n*1e12))\n",
      "print(\"printprint Capacitive susceptance = %.2fe-6 mho per mi per phase to neutral\" %(B_c*1e6))"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "printprint Capacitance = 18.812e-12 F/m printprint\n",
        "printprint Capacitive susceptance = 11.41e-6 mho per mi per phase to neutral\n"
       ]
      }
     ],
     "prompt_number": 17
    }
   ],
   "metadata": {}
  }
 ]
}