1
|
{"nbformat_minor": 0, "cells": [{"source": "#Chapter5 : Electrical Machines", "cell_type": "markdown", "metadata": {}}, {"source": "##Example 5.1 , Page number 178", "cell_type": "markdown", "metadata": {}}, {"execution_count": 1, "cell_type": "code", "source": "#determine the induced emf in the armature\n\n#varaible declaration\nP=4 #poles\nA=2 #wave wound\nn=50 #number of slots\nSc=24 #slots/conductor\nN=600 #speed of armature \nF=10e-3 #webers\n\n#calculations\nZ=Sc*n #total conductor\nE=F*Z*N*P/(60*A) #emf induced\n\nprint \" emf induced E = \" , E , \"volts\"\n", "outputs": [{"output_type": "stream", "name": "stdout", "text": " emf induced E = 240.0 volts\n"}], "metadata": {"collapsed": false, "trusted": true}}, {"source": "##Example 5.2 , Page number 178", "cell_type": "markdown", "metadata": {}}, {"execution_count": 2, "cell_type": "code", "source": "#determine the induced emf in the armature\n\n#variable declaration\nP=4 #poles\nA=4 #wave wound\nn=50 #number of slots\nSc=24 #slots/conductor\nN=600 #rpm \nF=10e-3 #webers\n\n#calculations\nZ=Sc*n;#total conductor\nE=F*Z*N*P/(60*A) #emf induced\n\n#result\nprint \"e.m.f induced E = \" , E, \"volts\"\n", "outputs": [{"output_type": "stream", "name": "stdout", "text": "e.m.f induced E = 120.0 volts\n"}], "metadata": {"collapsed": false, "trusted": true}}, {"source": "##Example 5.3 , Page number 179", "cell_type": "markdown", "metadata": {}}, {"execution_count": 3, "cell_type": "code", "source": "#determine the speed\n\n#variable declaration\nP=6 #poles\nA1=2 #wave wound\nZ=780 #armature conductors\nF=12*10**-3 #webers \nE=400 #volt\nA2=6 #wave wound\n#calculation\nN=(E*60*A1)/(F*Z*P) #rpm\nN2=(E*60*A2)/(F*Z*P) #rpm\n\n#result\nprint \" Speed of the armature = \" , round(N,2) , \"rpm\"\nprint \" Speed when lap is wound = \" , round(N2,1) , \"rpm\"\n", "outputs": [{"output_type": "stream", "name": "stdout", "text": " Speed of the armature = 854.7 rpm\n Speed when lap is wound = 2564.1 rpm\n"}], "metadata": {"collapsed": false, "trusted": true}}, {"source": "##Example 5.4 , Page number 182", "cell_type": "markdown", "metadata": {}}, {"execution_count": 4, "cell_type": "code", "source": "#determine the emf induced\n\n#variable declaration\nR=0.5 #ohm\nRs=100.0 \nV=250.0 #volts\nP=10000.0 #watts\n\n#calculation\nI=P/V #ampere\nIs=V/Rs \nIa=I+Is \nEg=V+(R*Ia) #volts\n\n#result\nprint \" emf induced Eg = \" , Eg , \"volts\"\n", "outputs": [{"output_type": "stream", "name": "stdout", "text": " emf induced Eg = 271.25 volts\n"}], "metadata": {"collapsed": false, "trusted": true}}, {"source": "##Example 5.5 , Page number 183", "cell_type": "markdown", "metadata": {}}, {"execution_count": 5, "cell_type": "code", "source": "#calculate the emf induced in the armature\n\n#variable declaration\nIl=200 #amperes\nVl=500 #volts\nRa=0.03 #ohm\nRs=0.015\nR=150\nBCD=2 #one volt per brush\n\n#calculation\nI=Vl/R #ampere\nIa=Il+I \nEg=Vl+(Ia*Ra)+(Ia*Rs)+BCD #volts\n\n#result\nprint \" emf induced Eg = \" , round(Eg,2) , \"volts\"\n\n#round off error in book\n", "outputs": [{"output_type": "stream", "name": "stdout", "text": " emf induced Eg = 511.13 volts\n"}], "metadata": {"collapsed": false, "trusted": true}}, {"source": "##Example 5.6 , Page number 184", "cell_type": "markdown", "metadata": {}}, {"execution_count": 6, "cell_type": "code", "source": "#calculate the emf induced in the armature\n\n#variable declaration\nI1=200 #ampere\nVl=500 #volts\nRa=0.03 #ohm\nRs=0.015\nIs=200 #ampere\nR=150 #ohm\n\n#calculation\nBCD=2 #one volt per brush\nI=(Vl+(Is*Rs))/R #ampere\nIa = I1 + I\nEg=Vl+(Ia*Ra)+(Ia*Rs)+BCD #volts\n\n#result\nprint \" emf induced Eg = \" , round(Eg,2) ,\"volts\"\n\n#Error in book\n", "outputs": [{"output_type": "stream", "name": "stdout", "text": " emf induced Eg = 511.15 volts\n"}], "metadata": {"collapsed": false, "trusted": true}}, {"source": "##Example 5.7 , Page number 196", "cell_type": "markdown", "metadata": {}}, {"execution_count": 7, "cell_type": "code", "source": "#calculate the back emf induced on full load\n\n#variable declaration\nRa=0.5 #armature resistance\nRs=250 #shunt resistance\nVl=250 #line volt\nIl=40 #ampere\n\n#calculation\nIs=Vl/Rs #amperes\nIa=Il-Is\nEb=Vl-(Ia*Ra) #volts\n\n#result\nprint \"emf induced Eb = \", Eb, \"volts\" \n", "outputs": [{"output_type": "stream", "name": "stdout", "text": "emf induced Eb = 230.5 volts\n"}], "metadata": {"collapsed": false, "trusted": true}}, {"source": "##Example 5.8 , Page number 196", "cell_type": "markdown", "metadata": {}}, {"execution_count": 8, "cell_type": "code", "source": "#find the power developed in circiut\n\n#variable declaration\nPl=20e3 #watts\nVl=200.0 #volts \nRa=0.05 #ohms\nR=150.0\n\n#calculation\nI=Vl/R #ampere\nIl=Pl/Vl\nIa=Il+I\nEg=Vl+(Ia*Ra) #volts\nP=Eg*Ia #watts\n\n#result\nprint \"power developed = \" , round(P,2) , \"watt\"\n\n#round off error in book\n", "outputs": [{"output_type": "stream", "name": "stdout", "text": "power developed = 20780.09 watt\n"}], "metadata": {"collapsed": false, "trusted": true}}, {"source": "##Example 5.9 , Page number 197", "cell_type": "markdown", "metadata": {}}, {"execution_count": 9, "cell_type": "code", "source": "#calculate the speed of the machine when running\n\n#variable declaration\nN1=1000 #speed of generator\nE1=205.06 #emf generator\nE2=195.06 #emf of motor\n\n#calculation\nN2=(E2*N1)/E1 #speed of generator\n\n#result\nprint\"speed of motor = \" , round(N2,2) ,\"rpm\"\n", "outputs": [{"output_type": "stream", "name": "stdout", "text": "speed of motor = 951.23 rpm\n"}], "metadata": {"collapsed": false, "trusted": true}}, {"source": "##Example 5.10 , Page number 198", "cell_type": "markdown", "metadata": {}}, {"execution_count": 10, "cell_type": "code", "source": "#dtermine its speed when its take crnt 25 amps\n\n#variable declaration\nVl=250.0 #volts\nRa=0.05 #ohm\nR=0.02 #ohm\nIa=30.0 #ampere\nI1=30.0\nN1=400.0\nI2=25.0\n\n#calculation\nE1=Vl-(Ia*Ra)-(Ia*R) #volts\nN2=(N1*E1*I1)/(E1*I2) #rpm\n\n#result\nprint \"speed of motor = \" , round(N2,2) ,\"rpm\"\n\n#round off error in book\n", "outputs": [{"output_type": "stream", "name": "stdout", "text": "speed of motor = 480.0 rpm\n"}], "metadata": {"collapsed": false, "trusted": true}}, {"source": "##Example 5.11 , Page number 199", "cell_type": "markdown", "metadata": {}}, {"execution_count": 11, "cell_type": "code", "source": "#find the torque whn its take scurnt 60amprs\n\n#variable declaration\nVl=200 #volts\nIl=60 #amperes\nR=50 #ohm\nf=0.03 # flux \nZ=700 #armature conductors\nP=4 #pole\nA=2\n\n#calculation\nI=Vl/R # amperes\nIa=Il-I #amperes\nT=(0.159*f*Z*Ia*P)/A\n\n#result\nprint \" Torque = \" , round(T,2) , \"N-m\"\n", "outputs": [{"output_type": "stream", "name": "stdout", "text": " Torque = 373.97 N-m\n"}], "metadata": {"collapsed": false, "trusted": true}}, {"source": "##Example 5.12 , Page number 214", "cell_type": "markdown", "metadata": {}}, {"execution_count": 12, "cell_type": "code", "source": "#calcute the num of prim turns and prim $sec current\n\n#variable declaration\nKVA = 50.0\nE1 = 6000.0 #volts\nE2 = 250.0 #volts\nN2 = 52.0 #number of turns\n\n#calculation\nN1=N2*E1/E2\nI2=KVA*1000/E2 #ampere\nI1=KVA*1000/E1 #ampere\n\n#result\nprint \" primary number of turns = \" , N1 , \"turns\"\nprint \" secondary current = \" , I2, \"amperes\"\nprint \" primary current = \" , round(I1,2), \"amperes\"\n", "outputs": [{"output_type": "stream", "name": "stdout", "text": " primary number of turns = 1248.0 turns\n secondary current = 200.0 amperes\n primary current = 8.33 amperes\n"}], "metadata": {"collapsed": false, "trusted": true}}, {"source": "##Example 5.13 , Page number 215", "cell_type": "markdown", "metadata": {}}, {"execution_count": 13, "cell_type": "code", "source": "#determine the emf induced in the secondry max value of flux density\n\n#calculation\nf=50 #Hz\nN1=350 #turns\nN2=800 #turns\nE1=400 #volts\nA=75e-4 #m**2\n\n#calculation\nE2=(N2*E1)/N1 #volts\nBm=E1/(4.44*f*A*N1) #Wb/m**2\n\n#result\nprint \" flux density = \" , round(Bm,3) , \"wb/m**2\"\n", "outputs": [{"output_type": "stream", "name": "stdout", "text": " flux density = 0.686 wb/m**2\n"}], "metadata": {"collapsed": false, "trusted": true}}, {"source": "##Example 5.14 , Page number 215", "cell_type": "markdown", "metadata": {}}, {"execution_count": 14, "cell_type": "code", "source": "import math\n\n#find the magnetic nd iron loss component of current\n\n#variable declaration\nE1=440 #volts\nE2=200 #volts\nI=0.2 #amperea\ncoso=0.18 #p.f.\n\n#calculation\nsino= math.sqrt(1-coso**2) \nIw=I*coso #ampere\nIu=I*sino #ampere\n\n#result\nprint \" Magnetising compenet of current = \" , round(Iw,3), \"amperes\"\nprint \" iron loss compenet of current = \" , round(Iu,4), \"amperes\"\n", "outputs": [{"output_type": "stream", "name": "stdout", "text": " Magnetising compenet of current = 0.036 amperes\n iron loss compenet of current = 0.1967 amperes\n"}], "metadata": {"collapsed": false, "trusted": true}}, {"source": "##Example 5.15 , Page number 216", "cell_type": "markdown", "metadata": {}}, {"execution_count": 15, "cell_type": "code", "source": "#calculate the efficiency at loads\n\n#variable declaration\nKVA=20\nIl=350 #iron loss\nCl=400 #copper loss\nx=1 # fraction of load\npf=0.8 # at full load\npf1=0.4 #at half load\nx1=0.5 #fraction of load\n\n#calculation\nop=KVA*1000*x*pf\nop1=KVA*1000*x1*pf1\nTl=Il+(Cl*x*x)\nTl1=Il+(Cl*x1*x1)\nip=op+Tl\nip1=op1+Tl1\nn=op/ip*100\nn1=op1/ip1*100\n\n#result\nprint \"efficiency at half load = \" , round(n,2) \nprint \"efficiency at full load = \" , round(n1,2) \n", "outputs": [{"output_type": "stream", "name": "stdout", "text": "efficiency at half load = 95.52\nefficiency at full load = 89.89\n"}], "metadata": {"collapsed": false, "trusted": true}}, {"source": "##Example 5.16 , Page number 221", "cell_type": "markdown", "metadata": {}}, {"execution_count": 16, "cell_type": "code", "source": "#calculate the synchronous speed ,slip,frequncy induced emf\n\n#variable declaration\nf=50.0 #Hz\np=4 #poles \nN=1460.0 #rpm\n\n#calculation\nNs=120*f/p #rpm\ns=(Ns-N)/Ns #slip\nf1=(s*f) #Hz\n\n#result\nprint \"synchronous speed Ns = \" , Ns , \"rpm\"\nprint \"slip s = \" , round(s,3)\nprint \" Frequency of rotor induced emf f = \" , round(f1,2) , \"Hz\"\n", "outputs": [{"output_type": "stream", "name": "stdout", "text": "synchronous speed Ns = 1500.0 rpm\nslip s = 0.027\n Frequency of rotor induced emf f = 1.33 Hz\n"}], "metadata": {"collapsed": false, "trusted": true}}, {"source": "##Example 5.17 , Page number 222", "cell_type": "markdown", "metadata": {}}, {"execution_count": 17, "cell_type": "code", "source": "#determine the value of slip nd speed of motor\n\n#variable declaration\nP=6 #pole\nf=50 #Hz\nf1=1.5\n\n#calculation\nNs=120*f/P\ns=f1/f\nN=Ns*(1-s)\n\n#result\nprint \" speed of motor = \", N, \" RPM\"\nprint \" slip = \" , round(s,3)\n", "outputs": [{"output_type": "stream", "name": "stdout", "text": " speed of motor = 970.0 RPM\n slip = 0.03\n"}], "metadata": {"collapsed": false, "trusted": true}}, {"source": "##Example 5.18 , Page number 222", "cell_type": "markdown", "metadata": {}}, {"execution_count": 18, "cell_type": "code", "source": "#calculate the numbers of poles ,slip at full load,frequncy rotor,speed of motor\n\n#variable declaration\nNs=1000.0 #rpm\nN=960\nf=50 #Hz\n\n#calculation\nP=120*f/Ns #synchronous speed\ns=(Ns-N)/Ns #slip \nf1=s*f #Hz\nN=Ns*(1-0.08) #speed of motor at 8% slip\n\n#result\nprint \" number of poles p = \" , P\nprint \" slip s = \" , round(s,2)\nprint \" Frequency of rotor emf f = \" , f , \"Hz\"\nprint \" Speed of motor at 8% slip N = \" , N , \"RPM\"\n", "outputs": [{"output_type": "stream", "name": "stdout", "text": " number of poles p = 6.0\n slip s = 0.04\n Frequency of rotor emf f = 50 Hz\n Speed of motor at 8% slip N = 920.0 RPM\n"}], "metadata": {"collapsed": false, "trusted": true}}, {"source": "##Example 5.19 , Page number 231", "cell_type": "markdown", "metadata": {}}, {"execution_count": 19, "cell_type": "code", "source": "#calculate the induced emf per phase\n\n#variable declaration\nf=50 #Hz\nP=16 #poles\nN=160 #rpm\nS=6 #slip\nF=0.025 #flux\n\n#calculation\nn=N*S #conductors\nZ=n/3 \ne=2.22*F*f*Z #rms value\n\n#result\nprint \"Induced emf per phase e = \" , e , \"volts\"\n", "outputs": [{"output_type": "stream", "name": "stdout", "text": "Induced emf per phase e = 888.0 volts\n"}], "metadata": {"collapsed": false, "trusted": true}}], "nbformat": 4, "metadata": {"kernelspec": {"display_name": "Python 2", "name": "python2", "language": "python"}, "language_info": {"mimetype": "text/x-python", "nbconvert_exporter": "python", "version": "2.7.8", "name": "python", "file_extension": ".py", "pygments_lexer": "ipython2", "codemirror_mode": {"version": 2, "name": "ipython"}}}}
|
