{ "metadata": { "name": "", "signature": "sha256:f5ac69af9ae1d841a7df309d87210c9fa6bb22448fba66aee7e2b96f7445f61f" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter3:THREE PHASE CIRCUITS" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex3.1:pg-286" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import cmath\n", "f=50.0; #Assigning values to parameters\n", "Vl=400.0;\n", "Rph=20.0;\n", "L=0.5;\n", "Xl=2*math.pi*f*L;\n", "Zph=20+1j*157;\n", "[r,t]=cmath.polar(Zph);\n", "Vph=Vl/sqrt(3); #Star connection\n", "Iph=Vph/r;\n", "Il=Iph;\n", "P=sqrt(3)*Vl*Il*cos(t);\n", "print\"The line current for Star connection is Il=\",round(Il,2),\"Amperes\"\n", "print\"The total power absorbed in Star connection is P=\",round(P,3),\"Watts\"\n", "Vph=Vl; #Delta connection\n", "Iph=Vph/r;\n", "Il=sqrt(3)*Iph;\n", "P=sqrt(3)*Vl*Il*cos(t);\n", "print\"The line current for Delta connection is Il=\",round(Il,2),\"Amperes\"\n", "print\"The total power absorbed in Delta connection is P=\",round(P,2),\"Watts\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The line current for Star connection is Il= 1.46 Amperes\n", "The total power absorbed in Star connection is P= 127.75 Watts\n", "The line current for Delta connection is Il= 4.38 Amperes\n", "The total power absorbed in Delta connection is P= 383.25 Watts\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex3.2:pg-288" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import cmath\n", "f=50 #Assigning values to parameters\n", "rph=8\n", "l=0.02\n", "xl=2*math.pi*f*l\n", "vl=230\n", "f=50\n", "vph=vl/sqrt(3)\n", "zph=8+1j*6.28\n", "[r,t]=cmath.polar(zph)\n", "iph=vph/r\n", "il=iph\n", "p=sqrt(3)*vl*il*cos(t)\n", "q=sqrt(3)*vl*il*sin(t)\n", "s=sqrt(3)*vl*il\n", "print\"The line current is il=\",round(il,2),\"Amperes\"\n", "print\"The total Power absorbed is P=\",round(P,2),\"Watts\"\n", "print\"The reactive volt amperes is q=\",round(q,2),\"VAR\"\n", "print\"The Volt amperes is s=\",round(s,2),\"Volt Ampere\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The line current is il= 13.06 Amperes\n", "The total Power absorbed is P= 383.25 Watts\n", "The reactive volt amperes is q= 3211.69 VAR\n", "The Volt amperes is s= 5201.33 Volt Ampere\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex3.3:pg-289" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import cmath\n", "Vl=230; #Assigning values to parameters\n", "f=50;\n", "Rph=15;\n", "L=0.03;\n", "Xl=2*math.pi*f*L;\n", "Zph=15+1j*9.42;\n", "[r,t]=cmath.polar(Zph)\n", "Vph=Vl;\n", "Iph=Vph/r;\n", "Il=sqrt(3)*Iph;\n", "P=sqrt(3)*Vl*Il*cos(t);\n", "print\"Phase current is Iph=\",round(Iph,2),\"Amperes\"\n", "print\"Line current is Il=\",round(Il,1),\"Amperes\"\n", "print\"Power absorbed is=\",round(P/1000,2),\"KW\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Phase current is Iph= 12.99 Amperes\n", "Line current is Il= 22.5 Amperes\n", "Power absorbed is= 7.59 KW\n" ] } ], "prompt_number": 22 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex3.4:pg-290" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import cmath\n", "f=50#assigning values to the parameters\n", "xc=200\n", "vph=400\n", "vl=vph\n", "zph=14.151-1j*200\n", "[r,t]=cmath.polar(zph)\n", "iph=vph/r\n", "il=sqrt(3)*iph\n", "p=sqrt(3)*vl*il*cos(t)\n", "pwr=vph*iph*cos(t)\n", "c=1.0/(2*math.pi*f*xc)\n", "print\"power consumed in each branch of delta is pwr=\",round(pwr,2),\"Watts\"\n", "print\"capacitive reactance is c=\"\"{:.2e}\".format(c),\"Farads\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "power consumed in each branch of delta is pwr= 56.32 Watts\n", "capacitive reactance is c=1.59e-05 Farads\n" ] } ], "prompt_number": 29 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex3.5:pg-290" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import cmath\n", "l=50 #Assigning values to parameters\n", "w=800\n", "c=50\n", "xl=w*l\n", "xc=1/(w*c)\n", "z1=0+1j*40\n", "z2=50\n", "z3=0-1j*25\n", "zph=z1+z2*z3/(z2+z3)\n", "[r,t]=cmath.polar(zph)\n", "vl=550\n", "vph=vl\n", "iph=vph/r\n", "il=sqrt(3)*iph\n", "p=sqrt(3)*vl*il*cos(t)\n", "pf=cos(t)\n", "q=sqrt(3)*vl*il*sin(t)\n", "s=sqrt(3)*vl*il\n", "print\"The phase current is\",round(iph,2),\"Amperes\"\n", "print\"The line current is\",round(il,2),\"Amperes\"\n", "print\"The power drawn is\",round(p/1000,2),\"kw\"\n", "print\"The power factor is\",round(pf,2)\n", "print\"The reactive power is\",round(q/1000,2),\"kw\"\n", "print\"The kva rating of load is\",round(s/1000,2),\"KVA\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The phase current is 24.6 Amperes\n", "The line current is 42.6 Amperes\n", "The power drawn is 18.15 kw\n", "The power factor is 0.45\n", "The reactive power is 36.3 kw\n", "The kva rating of load is 40.58 KVA\n" ] } ], "prompt_number": 39 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex3.7:pg-294" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import cmath\n", "p=10000 #Assigning values to parameters\n", "t=math.acos(0.6)\n", "vl=440\n", "vph=vl\n", "il=p/(sqrt(3)*vl*cos(t))\n", "iph=il/sqrt(3)\n", "zph=vph/iph\n", "zph1=20.9-1j*27.87\n", "res=zph1.real\n", "xc=zph1.imag\n", "q=sqrt(3)*vl*il*sin(t)\n", "print\"The resistance value of circuit element is\",round(res,2),\"ohms\"\n", "print\"The capacitive value of circuit element is\",round(-xc,2),\"ohms\"\n", "print\"The reactive volt-ampere\",round(-q/1000,2),\"KVAR\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The resistance value of circuit element is 20.9 ohms\n", "The capacitive value of circuit element is 27.87 ohms\n", "The reactive volt-ampere -13.33 KVAR\n" ] } ], "prompt_number": 50 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex3.8:pg-295" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import cmath\n", "f=50 #Assigning values to parameters\n", "vl=440\n", "p=1500\n", "t=math.acos(0.2)\n", "vph=vl/sqrt(3)\n", "il=p/(sqrt(3)*vl*p*cos(t))\n", "iph=il\n", "zph=vph/iph\n", "zph1=5.17+1j*25.3\n", "res=zph1.real\n", "xl=zph1.imag\n", "l=xl/(2*math.pi*f)\n", "print\"The resistive circuit constant is\",round(res,2),\"ohms\"\n", "print\"The inductive circuit constant is\",round(l,2),\"H\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The resistive circuit constant is 5.17 ohms\n", "The inductive circuit constant is 0.08 H\n" ] } ], "prompt_number": 52 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex3.9:pg-296" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import cmath\n", "p=100000 #Assigning values to parameters\n", "il=80\n", "vl=1100\n", "f=50\n", "vph=vl/sqrt(3)\n", "iph=il\n", "zph=vph/iph\n", "t=math.acos(p/(sqrt(3)*vl*il))\n", "zph1=5.21-1j*6\n", "r=zph1.real\n", "xc=zph1.imag\n", "c=1/(2*math.pi*f*xc)\n", "print\"The resistive circuit constant is\",round(r,2),\"ohms\"\n", "print\"The capacitive circuit constant is\",round(-xc,2),\"ohms\"\n", "print\"The capacitance is\",\"{:.2e}\".format(-c),\"farads\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The resistive circuit constant is 5.21 ohms\n", "The capacitive circuit constant is 6.0 ohms\n", "The capacitance is 5.31e-04 farads\n" ] } ], "prompt_number": 58 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex3.10:pg-296" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "Vl=400; #Assigning values to parameters\n", "Il=34.65;\n", "P=14.4*10**3;\n", "Vph=Vl;\n", "Iph=Il/sqrt(3);\n", "Zph=Vph/Iph;\n", "t=math.acos(P/(sqrt(3)*Vl*Il))\n", "Z=complex(Zph,t);\n", "a=cmath.rect(Zph,t)\n", "print\"Impedance\",a,\"ohms\"\n", "print \"Resistance\",round(a.real),\"ohms\"\n", "print \"Reactance\",round(a.imag),\"ohms\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Impedance (11.9937782275+15.9981840036j) ohms\n", "Resistance 12.0 ohms\n", "Reactance 16.0 ohms\n" ] } ], "prompt_number": 79 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex3.11:pg-297" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import cmath\n", "vl=415 #assigning values to the parameters\n", "r=15\n", "l=0.1\n", "c=177*10**-6\n", "f=50\n", "vph=vl/sqrt(3)\n", "xl=2*math.pi*f*l\n", "xc=1.0/(2*math.pi*f*c)\n", "a=xl-xc\n", "zph=r+1j*a\n", "[r1,t]=cmath.polar(zph)\n", "iph=vph/r1\n", "il=iph\n", "p=sqrt(3)*vl*il*cos(t)\n", "q=sqrt(3)*vl*il*sin(t)\n", "s=sqrt(3)*vl*il\n", "print\"The phase current is\",round(iph,1),\"Amperes\"\n", "print\"The line current is\",round(il,2),\"Amperes\"\n", "print\"The power drawn is\",round(p/1000,2),\"KW\"\n", "print\"The reactive power is\",round(q/1000,2),\"KVAR\"\n", "print\"The total kVA is\",round(s/1000,2),\"KVA\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The phase current is 11.9 Amperes\n", "The line current is 11.9 Amperes\n", "The power drawn is 6.37 KW\n", "The reactive power is 5.71 KVAR\n", "The total kVA is 8.55 KVA\n" ] } ], "prompt_number": 102 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex3.12:pg-299" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "vl=400 #assigning values to the parameters\n", "t=0\n", "zph=50\n", "vph=vl/sqrt(3)\n", "iph=vph/zph\n", "il=iph\n", "p=sqrt(3)*vl*il*cos(t)\n", "print\"Power taken is\",round(p,2),\"Watts\"\n", "iph=4\n", "il=iph\n", "p=vl*il*cos(t)\n", "print\"Power taken after disconecting one of the resistor is\",round(p,2),\"Watts\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Power taken is 3200.0 Watts\n", "Power taken after disconecting one of the resistor is 1600.0 Watts\n" ] } ], "prompt_number": 103 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex3.13:pg-300" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "vl=400 #Assigning values to parameters\n", "vph=vl\n", "r=40\n", "t=0\n", "iph=vph/r\n", "il=sqrt(3)*iph\n", "p=sqrt(3)*vl*il*cos(t)\n", "print\"Power taken is\",round(p,2),\"Watts\"\n", "i=10\n", "p=2*i*i*r\n", "print\"Power taken after diconnecting one resistor is\",round(p,2),\"Watts\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Power taken is 12000.0 Watts\n", "Power taken after diconnecting one resistor is 8000.0 Watts\n" ] } ], "prompt_number": 104 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex3.16:pg-310" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "w1=500 #Assigning values to parameters\n", "w2=2500\n", "p=w1+w2\n", "t=math.atan(sqrt(3)*(w2-w1)/(w1+w2))\n", "pf=cos(t)\n", "print\"Total Power supplied is\",round(p,2),\"Watts\"\n", "print\"Power factor is\",round(pf,3)\n", "w2=2500\n", "w1=-500\n", "p=w1+w2\n", "t=math.atan(sqrt(3)*(w2-w1)/(w1+w2))\n", "pf=cos(t)\n", "print\"Total Power supplied after reversing the connections to the current coil is\",round(p,2),\"Watts\"\n", "print\"Power factor after reversing the connections to the current coil is\",round(pf,3)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Total Power supplied is 3000.0 Watts\n", "Power factor is 0.655\n", "Total Power supplied after reversing the connections to the current coil is 2000.0 Watts\n", "Power factor after reversing the connections to the current coil is 0.359\n" ] } ], "prompt_number": 117 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex3.17:pg-311" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "w1=3000 #Assigning values to parameters\n", "w2=5000\n", "t=math.atan(sqrt(3)*(w2-w1)/(w1+w2))\n", "pf=cos(t)\n", "p=w1+w2\n", "il=p/(sqrt(3)*vl*cos(t))\n", "print\"Watts\",p,\"Total Power supplied is\",round(p,2),\"Watts\"\n", "print\"Power factor is\",round(pf,2)\n", "print\"The line current is\",round(il,2),\"Amperes\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Watts 8000 Total Power supplied is 8000.0 Watts\n", "Power factor is 0.92\n", "The line current is 12.58 Amperes\n" ] } ], "prompt_number": 112 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "\n", "Ex3.18:pg-311" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "w1=-1000 #Assigning values to parameters\n", "w2=3000\n", "vl=400\n", "t=math.atan(sqrt(3)*(w2-w1)/(w1+w2))\n", "pf=cos(t)\n", "p=w1+w2\n", "il=p/(sqrt(3)*vl*cos(t))\n", "print\"Total Power supplied is\",round(p,2),\"Watts\"\n", "print\"Power factor is\",round(pf,3)\n", "print\"The line current is\",round(il,2),\"Amperes\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Total Power supplied is 2000.0 Watts\n", "Power factor is 0.277\n", "The line current is 10.41 Amperes\n" ] } ], "prompt_number": 119 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "\n", "Ex3.19:pg-312" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "w1=100000 #Assigning values to parameters\n", "w2=300000\n", "vl=2000\n", "n=0.9\n", "t=math.atan(sqrt(3)*(w2-w1)/(w1+w2))\n", "pf=cos(t)\n", "p=w1+w2\n", "il=p/(sqrt(3)*vl*cos(t))\n", "print\"Total Power supplied is\",round(p,2),\"Watts\"\n", "print\"Power factor is\",round(pf,2)\n", "print\"The line current is\",round(il,2),\"Amperes\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Total Power supplied is 400000.0 Watts\n", "Power factor is 0.76\n", "The line current is 152.75 Amperes\n" ] } ], "prompt_number": 121 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "\n", "Ex3.20:pg-312" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "vl=220 #Assigning values to parameters\n", "il=38\n", "n=0.88\n", "p=11200\n", "ip=p/n\n", "t=math.acos(ip/(sqrt(3)*vl*il))\n", "a=math.degrees(t)\n", "w2=vl*il*cos(30-a)\n", "w1=vl*il*cos(30+a)\n", "print\"The wattmeter reading is w2=\",round(w2,2),\"Watts\"\n", "print\"The wattmeter reading is w1=\",round(w1,2),\"Watts\"\n", "# the answer of w2,w1 are wrong in the book\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The wattmeter reading is w2= 449.52 Watts\n", "The wattmeter reading is w1= -2972.66 Watts\n" ] } ], "prompt_number": 138 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "\n", "Ex3.21:pg-313" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "w1=1 #Assigning values to parameters\n", "w2=2*w1\n", "t=math.atan(sqrt(3)*(w2-w1)/(w1+w2))\n", "pf=cos(t)\n", "print\"Power factor is\",round(pf,3)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Power factor is 0.866\n" ] } ], "prompt_number": 127 } ], "metadata": {} } ] }