{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "CHAPTER 2.6: INTERFERENCE OF POWER LINES WITH NEIGHBOURING COMMUNICATION CIRCUITS" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.6.1, Page number 206" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Variable declaration\n", "f = 50.0 #Frequency(Hz)\n", "d = 4.0 #Spacing b/w conductors(m)\n", "D = 2.0 #Distance of telephone line below conductor(m)\n", "s = 60.0/100 #Spacing b/w telephone line(m)\n", "r = 2.0 #Radius of power line(mm)\n", "I = 150.0 #Current in power line(A)\n", "\n", "#Calculation\n", "D_ac = (D**2+((d-s)/2)**2)**0.5 #Distance b/w a & c(m)\n", "D_ad = (D**2+(((d-s)/2)+s)**2)**0.5 #Distance b/w a & d(m)\n", "M = 4.0*10**-7*math.log(D_ad/D_ac)*1000 #Mutual inductance b/w circuits(H/km)\n", "V_CD = 2.0*math.pi*f*M*I #Voltage induced in the telephone line(V/km)\n", "\n", "#Result\n", "print('Mutual inductance between the circuits, M = %.e H/km' %M)\n", "print('Voltage induced in the telephone line, V_CD = %.2f V/km' %V_CD)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Mutual inductance between the circuits, M = 6e-05 H/km\n", "Voltage induced in the telephone line, V_CD = 2.82 V/km\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.6.2, Page number 206-207" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Variable declaration\n", "f = 50.0 #Frequency(Hz)\n", "l = 160.0 #Length of line(km)\n", "V = 132.0*10**3 #Line voltage(V)\n", "P = 25.0*10**6 #Load delivered(W)\n", "PF = 0.8 #Lagging power factor\n", "r = 5.0/1000 #Radius of power line conductor(m)\n", "d = 4.0 #Spacing b/w conductors(m)\n", "OS = 6.0 #Distance(m)\n", "OT = 6.5 #Distance(m)\n", "CT = 18.0 #Distance(m)\n", "\n", "#Calculation\n", "AO = 3**0.5*d/2.0 #Distance A to O(m). From figure E6.2\n", "AS = OS+AO #Distance A to S(m)\n", "AT = AO+OT #Distance A to T(m)\n", "OB = d/2.0 #Distance O to B(m)\n", "BS = (OB**2+OS**2)**0.5 #Distance B to S(m)\n", "BT = (OB**2+OT**2)**0.5 #Distance B to T(m)\n", "M_A = 0.2*math.log(AT/AS) #Mutual inductance at A(mH/km)\n", "M_B = 0.2*math.log(BT/BS) #Mutual inductance at B(mH/km)\n", "M = M_B-M_A #Mutual inductance at C(mH/km)\n", "I = P/(3**0.5*V*PF) #Current(A)\n", "E_m = 2.0*math.pi*f*M*I*10**-3*l #Induced voltage(V)\n", "V_A = V/3**0.5 #Phase voltage(V)\n", "h = AO+CT #Height(m)\n", "V_SA = V_A*math.log10(((2*h)-AS)/AS)/math.log10(((2*h)-r)/r) #Potential(V)\n", "H = CT #Height(m)\n", "V_B = V_A #Phase voltage(V)\n", "V_SB = V_B*math.log10(((2*H)-BS)/BS)/math.log10(((2*H)-r)/r) #Potential(V)\n", "V_S = V_SB-V_SA #Total potential of S w.r.t earth(V)\n", "\n", "#Result\n", "print('Induced voltage at fundamental frequency, E_m = %.1f V' %E_m)\n", "print('Potential of telephone conductor S above earth, V_S = %.f V' %V_S)\n", "print('\\nNOTE: ERROR: Changes in obtained answer is due to precision and calculation mistakes in textbook')" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Induced voltage at fundamental frequency, E_m = 29.0 V\n", "Potential of telephone conductor S above earth, V_S = 2638 V\n", "\n", "NOTE: ERROR: Changes in obtained answer is due to precision and calculation mistakes in textbook\n" ] } ], "prompt_number": 1 } ], "metadata": {} } ] }