{ "metadata": { "name": "", "signature": "sha256:28034dbb342684d685a8a92f980deb80fefbb2dbd59fa3d7d9f9191f36310311" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 12 : Polyphase Circuits" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.2 Page No : 245" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "from scipy.linalg import polar\n", "\n", "# Given\n", "#The system ABC is DELTA connected\")\n", "#Effective line voltage is 120V\")\n", "#The three impedances are 5(45 deg)\")\n", "Zmag = 5;Zph = 45;\n", "#Let maximum line voltage is Vmax\n", "Vmax = 120*math.sqrt(2)\n", "#From fig 12.7(a)\n", "#VAB = Vmax(120 deg)\n", "#VBC = Vmax(0 deg)\n", "#VCA = Vmax(240 deg)\n", "\n", "#From figure 12.8\n", "IABmag = Vmax/Zmag\n", "IABph = 120-Zph\n", "print \"IAB = %3.2f%d deg)\"%(IABmag,IABph);\n", "\n", "IBCmag = Vmax/Zmag\n", "IBCph = 0-Zph\n", "print \"IBC = %3.2f%d deg)\"%(IBCmag,IBCph);\n", "\n", "ICAmag = Vmax/Zmag\n", "ICAph = 240-Zph\n", "print \"ICA = %3.2f%d deg)\"%(ICAmag,ICAph);\n", "\n", "#Applying KCL equation \n", "#IA = IAB+IAC\n", "#IB = IBC+IBA\n", "#IC = ICA+ICB\n", "\n", "x = IABmag*math.cos((IABph*math.pi)/180);\n", "y = IABmag*math.sin((IABph*math.pi)/180);\n", "z = complex(x,y)\n", "\n", "x1 = ICAmag*math.cos((ICAph*math.pi)/180);\n", "y1 = ICAmag*math.sin((ICAph*math.pi)/180);\n", "z1 = complex(x1,y1)\n", "\n", "x2 = IBCmag*math.cos((IBCph*math.pi)/180);\n", "y2 = IBCmag*math.sin((IBCph*math.pi)/180);\n", "z2 = complex(x2,y2)\n", "\n", "IA = z-z1;\n", "RA,ThetaA = polar([[IA]])\n", "RA = RA[0][0].real\n", "ThetaA = ThetaA[0][0].real\n", "\n", "IB = z2-z;\n", "RB,ThetaB = polar([[IB]])\n", "RB = RB[0][0].real\n", "ThetaB = ThetaB[0][0].real\n", "\n", "IC = z1-z2\n", "RC,ThetaC = polar([[IC]])\n", "RC = RC[0][0].real\n", "ThetaC = ThetaC[0][0].real\n", "\n", "#Therefore\")\n", "\n", "print \"IA = %3.2f%d deg)A\"%(RA,(ThetaA*180/math.pi));\n", "print \"IB = %3.2f%d deg)A\"%(RB,(ThetaB*180/math.pi));\n", "print \"IC = %3.2f%d deg)A\"%(RC,(ThetaC*180/math.pi));" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "IAB = 33.9475 deg)\n", "IBC = 33.94-45 deg)\n", "ICA = 33.94195 deg)\n", "IA = 0.713368 deg)A\n", "IB = 0.263368 deg)A\n", "IC = -0.973368 deg)A\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.5 Page No : 250" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "from scipy.linalg import polar\n", "#Example 12.5\")\n", "\n", "# Given\n", "#The system ABC is DELTA connected\")\n", "#Maximum line voltage is 339.4V\")\n", "#The three impedances are 10(0 deg),10(30 deg),15(-30 deg)\")\n", "\n", "ZABmag = 10;ZABph = 0;\n", "ZBCmag = 10;ZBCph = 30;\n", "ZCAmag = 15;ZCAph = -30;\n", "#Let maximum line voltage is Vmax\n", "Vmax = 339.4\n", "#From fig 12.7(a)\n", "#VAB = Vmax(120 deg)\n", "#VBC = Vmax(0 deg)\n", "#VCA = Vmax(240 deg)\n", "\n", "#From figure 12.15\n", "IABmag = Vmax/ZABmag\n", "IABph = 120-ZABph\n", "print \"IAB = %3.2f%d deg)\"%(IABmag,IABph);\n", "\n", "IBCmag = Vmax/ZBCmag\n", "IBCph = 0-ZBCph\n", "print \"IBC = %3.2f%d deg)\"%(IBCmag,IBCph);\n", "\n", "ICAmag = Vmax/ZCAmag\n", "ICAph = 240-ZCAph\n", "print \"ICA = %3.2f%d deg)\"%(ICAmag,ICAph);\n", "\n", "#Applying KCL equation \n", "#IA = IAB+IAC\n", "#IB = IBC+IBA\n", "#IC = ICA+ICB\n", "\n", "x = IABmag*math.cos((IABph*math.pi)/180);\n", "y = IABmag*math.sin((IABph*math.pi)/180);\n", "z = complex(x,y)\n", "\n", "x1 = ICAmag*math.cos((ICAph*math.pi)/180);\n", "y1 = ICAmag*math.sin((ICAph*math.pi)/180);\n", "z1 = complex(x1,y1)\n", "\n", "x2 = IBCmag*math.cos((IBCph*math.pi)/180);\n", "y2 = IBCmag*math.sin((IBCph*math.pi)/180);\n", "z2 = complex(x2,y2)\n", "\n", "IA = z-z1;\n", "RA,ThetaA = polar([[IA]])\n", "RA = RA[0][0].real\n", "ThetaA = ThetaA[0][0].real\n", "\n", "IB = z2-z;\n", "RB,ThetaB = polar([[IB]])\n", "RB = RB[0][0].real\n", "ThetaB = ThetaB[0][0].real\n", "\n", "IC = z1-z2\n", "RC,ThetaC = polar([[IC]])\n", "RC = RC[0][0].real\n", "ThetaC = ThetaC[0][0].real\n", "\n", "#Therefore\")\n", "\n", "print \"IA = %3.2f%d deg)A\"%(RA,(ThetaA*180/math.pi));\n", "print \"IB = %3.2f%d deg)A\"%(RB,(ThetaB*180/math.pi));\n", "print \"IC = %3.2f%d deg)A\"%(RC,(ThetaC*180/math.pi));" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "IAB = 33.94120 deg)\n", "IBC = 33.94-30 deg)\n", "ICA = 22.63270 deg)\n", "IA = -0.313135 deg)A\n", "IB = 0.713756 deg)A\n", "IC = -0.981714 deg)A\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.6 Page No : 252" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "from scipy.linalg import polar\n", "\n", "# Given\n", "#The system CBA is WYE connected\")\n", "#Maximum line voltage is 150V\")\n", "#The three impedances are 6(0 deg),6(30 deg),5(45 deg)\")\n", "ZAmag = 6;ZAph = 0;\n", "ZBmag = 6;ZBph = 30;\n", "ZCmag = 5;ZCph = 45;\n", "#Let maximum line voltage is Vmax\n", "Vmax = 150\n", "#Let the line to neutral voltage magnitude be Vn\n", "Vn = Vmax/math.sqrt(3)\n", "#From fig 12.7(b)\n", "#VAN = Vn(-90 deg)\n", "#VBN = Vn(30 deg)\n", "#VCN = Vn(150 deg)\n", "\n", "#From figure 12.16\n", "IAmag = Vn/ZAmag\n", "IAph = -90-ZAph\n", "print \"IA = %3.2f%d deg)A\"%(IAmag,IAph);\n", "\n", "IBmag = Vn/ZBmag\n", "IBph = 30-ZBph\n", "print \"IB = %3.2f%d deg)A\"%(IBmag,IBph);\n", "\n", "ICmag = Vn/ZCmag\n", "ICph = 150-ZCph\n", "print \"IC = %3.2f%d deg)A\"%(ICmag,ICph);\n", "\n", "#Now to calculate IN\n", "#IN = -(IA+IB+IC)\n", "x = IAmag*math.cos((IAph*math.pi)/180);\n", "y = IAmag*math.sin((IAph*math.pi)/180);\n", "z = complex(x,y)\n", "\n", "x1 = ICmag*math.cos((ICph*math.pi)/180);\n", "y1 = ICmag*math.sin((ICph*math.pi)/180);\n", "z1 = complex(x1,y1)\n", "\n", "x2 = IBmag*math.cos((IBph*math.pi)/180);\n", "y2 = IBmag*math.sin((IBph*math.pi)/180);\n", "z2 = complex(x2,y2)\n", "\n", "IN = -(z+z1+z2)\n", "\n", "R,Theta = polar([[IN]])\n", "R = R[0][0].real\n", "Theta = Theta[0][0].real\n", "\n", "\n", "print \"IN = %3.2f%d deg)A\"%(R,(Theta*180/math.pi));\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "IA = 14.43-90 deg)A\n", "IB = 14.430 deg)A\n", "IC = 17.32105 deg)A\n", "IN = -0.97585 deg)A\n" ] } ], "prompt_number": 9 } ], "metadata": {} } ] }