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diff --git a/A Textbook of Electrical Technology AC and DC Machines/chapter31.ipynb b/A Textbook of Electrical Technology AC and DC Machines/chapter31.ipynb new file mode 100644 index 00000000..aebdac51 --- /dev/null +++ b/A Textbook of Electrical Technology AC and DC Machines/chapter31.ipynb @@ -0,0 +1,1094 @@ +{ + "metadata": { + "name": "", + "signature": "sha256:7d0991402755fd2e3c1083bccec70e0a43143da000e9a99e70877269e1fdc43a" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "heading", + "level": 1, + "metadata": {}, + "source": [ + "Chapter 31: Testing of DC Machines" + ] + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example Number 31.1, Page Number:1092" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "#variable declaration\n", + "l=38.1#kg\n", + "d=63.53*0.01#cm\n", + "v=12#rps\n", + "i=49#A\n", + "V=220#V\n", + "\n", + "#calculations\n", + "r=d/2\n", + "torque=l*r*9.81\n", + "power=torque*2*3.14*v\n", + "motor_input=i*V\n", + "efficiency=power*100/motor_input\n", + "\n", + "#result\n", + "print \"Output power=\",round(power),\"W\"\n", + "print \"Efficiency=\",round(efficiency),\"%\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Output power= 8947.0 W\n", + "Efficiency= 83.0 %\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example Number 31.2(a), Page Number:1093" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "#variable declaration\n", + "spring_b1=10.0#kg\n", + "spring_b2=35.0#kg\n", + "d=40*0.01#m\n", + "v=950.0#rpm\n", + "V=200.0#V\n", + "i=30.0#A\n", + "\n", + "#calculations\n", + "F=(spring_b2-spring_b1)*9.81\n", + "N=v/60\n", + "R=d/2\n", + "tsh=F*R\n", + "omega=2*3.14*N\n", + "output=tsh*omega\n", + "motor_input=V*i\n", + "efficiency=output/motor_input\n", + "\n", + "#result\n", + "print \"output power=\",output,\"W\"\n", + "print \"efficiency=\",efficiency*100,\"%\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "output power= 4877.205 W\n", + "efficiency= 81.28675 %\n" + ] + } + ], + "prompt_number": 9 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example Number 31.2(b), Page Number:1093" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "#variable declaration\n", + "t1=2.9#kg\n", + "t2=0.17#kg\n", + "r=7*0.01#m\n", + "i=2.0#A\n", + "V=230.0#V\n", + "n=1500.0#rpm\n", + "\n", + "#calculations\n", + "force=(t1-t2)*9.81\n", + "torque=force*r\n", + "output=torque*2*3.14*n/60\n", + "efficiency=output/(V*i)\n", + "\n", + "#result\n", + "print \"torque=\",torque,\"N-m\"\n", + "print \"output\",output,\"W\"\n", + "print \"efficiency\",efficiency*100,\"%\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "torque= 1.874691 N-m\n", + "output 294.326487 W\n", + "efficiency 63.984018913 %\n" + ] + } + ], + "prompt_number": 15 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example Number 31.3, Page Number:1095" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "#variable declaration\n", + "V=220.0#V\n", + "i=2.5#A\n", + "ra=0.8#ohm\n", + "rsh=200.0#ohm\n", + "I=20.0#A\n", + "\n", + "#calculations\n", + "input_noload=V*i\n", + "ish=V/rsh\n", + "ia0=i-ish\n", + "culoss=ia0**2*ra\n", + "constant_loss=input_noload-culoss\n", + "ia=32-ish\n", + "cu_lossa=ia**2*ra\n", + "total_loss=cu_lossa+constant_loss\n", + "input_=V*I\n", + "output=input_-total_loss\n", + "efficiency=(output/input_)*100\n", + "\n", + "#result\n", + "print \"Efficiency=\",efficiency,\"%\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Efficiency= 70.1754545455 %\n" + ] + } + ], + "prompt_number": 22 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example Number 31.4, Page Number:1096" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "#variable declaration\n", + "V=400.0#V\n", + "i=5.0#A\n", + "ra=0.5#ohm\n", + "r=200.0#ohm\n", + "I=50.0#A\n", + "\n", + "#calculations\n", + "input_nl=V*i\n", + "ish=V/r\n", + "ia=i-ish\n", + "cu_loss=ia**2*ra\n", + "constant_loss=input_nl-cu_loss\n", + "Ia=I-ish\n", + "cu_lossa=Ia**2*ra\n", + "total_loss=constant_loss+cu_lossa\n", + "input_nl1=V*I\n", + "output=input_nl1-total_loss\n", + "efficiency=output/input_nl\n", + "Eb1=V-(ia*ra)\n", + "Eb2=V-(Ia*ra)\n", + "change=math.fabs((Eb1-Eb2)/Eb1)\n", + "\n", + "#result\n", + "print \"output=\",output,\"W\"\n", + "print \"efficiency=\",efficiency*10,\"%\"\n", + "print \"percentage change in speed=\",change*100,\"%\"\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "output= 16852.5 W\n", + "efficiency= 84.2625 %\n", + "percentage change in speed= 5.64617314931 %\n" + ] + } + ], + "prompt_number": 38 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example Number 31.5, Page Number:1096" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "from sympy.solvers import solve\n", + "from sympy import Symbol\n", + "#variable declaration\n", + "I=Symbol('I')\n", + "v=220#V\n", + "p=44.76#kW\n", + "i=13.25#A\n", + "ish=2.55#A\n", + "ra=0.032#ohm\n", + "bd=2#V\n", + "\n", + "#calculations\n", + "p_nl=v*i\n", + "ia=i-ish\n", + "cu_loss=ia**2*ra\n", + "bd_loss=2*ia\n", + "variable_loss=bd_loss+cu_loss\n", + "w=p_nl-variable_loss\n", + "ans=solve([v*(I+ish)-p*1000-w-2*I-ra*I**2],[I])\n", + "il=ans[0][0]+ish\n", + "pin=il*v\n", + "e=p*1000/pin\n", + "\n", + "#result\n", + "print \"Full load current=\",round(il),\"A\"\n", + "print \"Full load efficiency=\",round(e*100),\"%\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Full load current= 226.0 A\n", + "Full load efficiency= 90.0 %\n" + ] + } + ], + "prompt_number": 15 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example Number 31.6, Page Number:1097" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "from sympy.solvers import solve\n", + "from sympy import Symbol\n", + "#variable declaration\n", + "I=Symbol('I')\n", + "v=200.0#V\n", + "o=17.158#kW\n", + "inpt=20.2#KW\n", + "rf=50.0#ohm\n", + "ra=0.06#ohm\n", + "o2=7.46#kW\n", + "\n", + "#calculations\n", + "loss1=inpt*1000.0-o*1000.0\n", + "ic=inpt*1000.0/v\n", + "ish=v/rf\n", + "ia=ic-ish\n", + "cu_loss=ia**2*ra\n", + "const_loss=loss1-cu_loss\n", + "ans=solve([v*(I+ish)-o2*1000.0-(ra*I**2)-const_loss],[I])\n", + "il=ans[0][0]+ish\n", + "pin=il*v/1000.0\n", + "e=o2*1000*100/(pin*1000)\n", + "\n", + "#result\n", + "print \"efficiency=\",round(e,1),\"%\"\n", + "print \"power input=\",round(il),\"A\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "efficiency= 74.1 %\n", + "power input= 50.0 A\n" + ] + } + ], + "prompt_number": 23 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example Number 31.7, Page Number:1097" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "from sympy.solvers import solve\n", + "from sympy import Symbol\n", + "#variable declaration\n", + "I=Symbol('I')\n", + "v=200.0#V\n", + "p=14.92#kW\n", + "ia=6.5#A\n", + "ish=2.2#A\n", + "i=70.0#A\n", + "pd=3.0#V\n", + "\n", + "#calculations\n", + "ic_nl=ia+ish\n", + "pi=v*ic_nl\n", + "cu_loss=v*ish\n", + "cu_lossa=ia**2*pd/i\n", + "const_loss=pi-cu_lossa\n", + "ans=solve([v*I+cu_loss-p*1000-const_loss-(pd/i)*I**2],[I])\n", + "ic=ans[0][0]+ish\n", + "pin=v*ic\n", + "e=p*1000*100/pin\n", + "\n", + "#result\n", + "print \"efficiency=\",round(e),\"%\"\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "efficiency= 88.0 %\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example Number 31.8, Page Number:1098" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "#variable declaration\n", + "p=200*1000.0#W\n", + "v=250.0#V\n", + "i1=36.0#A\n", + "I1=12.0#A\n", + "v1=250.0#V\n", + "pd=6.0#V\n", + "i2=400.0#A\n", + "\n", + "#calculations\n", + "#no load\n", + "ia=i1-I1\n", + "ra=pd/i2\n", + "cu_loss=ia**2*ra\n", + "input_nl=v*i1\n", + "constant_loss=input_nl-cu_loss\n", + "\n", + "#full load\n", + "output_i=p/v\n", + "ia=output_i+I1\n", + "cu_lossa=ia**2*ra\n", + "total_loss=cu_lossa+constant_loss\n", + "efficiency=p/(p+total_loss)\n", + "#result\n", + "print \"efficiency at full load=\",efficiency*100,\"%\"\n", + "\n", + "#half load\n", + "output_i=p/(2*v)\n", + "ia=output_i+I1\n", + "cu_lossa=ia**2*ra\n", + "total_loss=cu_lossa+constant_loss\n", + "efficiency=p/((p/2+total_loss)*2)\n", + "\n", + "#result\n", + "print \"efficiency at half load=\",efficiency*100,\"%\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "efficiency at full load= 91.3736344667 %\n", + "efficiency at half load= 89.6559292335 %\n" + ] + } + ], + "prompt_number": 42 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example Number 31.9, Page Number:1098" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "#variable declaration\n", + "v=250.0#V\n", + "p=14.92*1000#W\n", + "e=0.88\n", + "n=700.0#rpn\n", + "rsh=100.0#ohm\n", + "i=78.0#A\n", + "\n", + "#calculations\n", + "input_=0.8*p/e\n", + "total_loss=input_-0.8*p\n", + "input_i=input_/v\n", + "ish=v/rsh\n", + "ia=input_i-ish\n", + "ra=total_loss/(2*(ia**2))\n", + "Ia=i-ish\n", + "total_loss2=Ia**2*ra+total_loss/2\n", + "input__=v*i\n", + "efficiency=(input__-total_loss2)*100/input__\n", + "Eb1=v-(ia*ra)\n", + "Eb2=v-(Ia*ra)\n", + "n2=(n*Eb2)/Eb1\n", + "\n", + "#result\n", + "print \"efficiency=\",efficiency,\"%\"\n", + "print \"speed=\",n2,\"r.p.m\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "efficiency= 86.9450046554 %\n", + "speed= 678.443304738 r.p.m\n" + ] + } + ], + "prompt_number": 48 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example Number 31.10(a), Page Number:1101" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "#variable declaration\n", + "v=220.0#V\n", + "p=100*1000.0#W\n", + "i2=90.0#A\n", + "\n", + "#calculations\n", + "i1=p/v\n", + "efficiency=math.sqrt(i1/(i1+i2))*100\n", + "\n", + "#result\n", + "print \"efficiency=\",round(efficiency,1),\"%\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "efficiency= 91.4 %\n" + ] + } + ], + "prompt_number": 2 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example Number 31.11, Page Number:1102" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "#variable declaration\n", + "i=15#A\n", + "v=200#V\n", + "motor_i=100#A\n", + "shunt_i1=3#A\n", + "shunt_i2=2.5#A\n", + "ra=0.05#ohm\n", + "cu_loss=500#W\n", + "cu_lossa=361#W\n", + "ia=85#A\n", + "#calculations\n", + "mech_core_stray_loss=0.5*((v*i)-(motor_i**2*ra)-(ia**2*ra))\n", + "cu_motor=v*shunt_i1\n", + "generator_motor=v*shunt_i2\n", + "total_loss=mech_core_stray_loss+cu_motor+generator_motor\n", + "input_=v*i+cu_motor\n", + "output=v*ia*10**(-3)\n", + "loss=cu_loss*10**(-3)+1.07+0.36\n", + "efficiency=output*100/(output+loss)\n", + "\n", + "#result\n", + "print \"eficiency=\",efficiency,\"%\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "eficiency= 89.8045430534 %\n" + ] + } + ], + "prompt_number": 52 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example Number 31.12, Page Number:1103" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "#variable declaration\n", + "v=110#V\n", + "i=48#A\n", + "i1=3#a\n", + "i2=3.5#A\n", + "motor_i=230#A\n", + "ra=0.035#ohm\n", + "\n", + "#calculations\n", + "#motor\n", + "cu_loss=motor_i**2*ra\n", + "brush_loss=motor_i*2\n", + "totalarm_culoss=cu_loss+brush_loss\n", + "shunt_cu=v*i1\n", + "total_cu_lossm=totalarm_culoss+shunt_cu\n", + "#generator\n", + "arm_i=233-i+i2\n", + "cu_loss=arm_i**2*ra\n", + "brush_loss=arm_i*2\n", + "totalarm_culoss=cu_loss+brush_loss\n", + "shunt_cu=v*i2\n", + "total_cu_lossg=totalarm_culoss+shunt_cu\n", + "#set\n", + "totalcu_loss=total_cu_lossm+total_cu_lossg\n", + "total_input=v*i\n", + "stray_loss=total_input-totalcu_loss\n", + "strayloss_per=stray_loss/2\n", + "#motor efficiency\n", + "input_=233*v\n", + "output=input_-(total_cu_lossm+strayloss_per)\n", + "e=output/input_*100\n", + "print \"motor efficiency=\",e,\"%\"\n", + "#generator efficiency\n", + "input_=110*185\n", + "output=input_-(total_cu_lossg+strayloss_per)\n", + "e=output/input_*100\n", + "100\n", + "print \"generator efficiency=\",e,\"%\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "motor efficiency= 88.4590884705 %\n", + "generator efficiency= 88.5893642506 %\n" + ] + } + ], + "prompt_number": 56 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example Number 31.13, Page Number:1103" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "#variable series\n", + "v=500.0#A\n", + "p=100*1000.0#w\n", + "auxiliary_i=30.0#A\n", + "output_i=200.0#A\n", + "i1=3.5#A\n", + "i2=1.8#A\n", + "ra=0.075#ohm\n", + "vdb=2.0#V\n", + "\n", + "#calculations\n", + "motor_arm=output_i+auxiliary_i\n", + "motorarm_culoss=(motor_arm**2*ra)+(motor_arm*2)\n", + "motorfield_culoss=v*i2\n", + "generatorarm_culoss=(output_i**2*ra)+(output_i*2)\n", + "generatoefield_culoss=v*i1\n", + "total_culoss=motorarm_culoss+motorfield_culoss+generatorarm_culoss+generatoefield_culoss\n", + "power=v*auxiliary_i\n", + "stray_loss=power-total_culoss\n", + "permachine=stray_loss/2\n", + "total_loss=generatorarm_culoss+generatoefield_culoss+permachine\n", + "output=v*output_i\n", + "e=output/(output+total_loss)\n", + "\n", + "#result\n", + "print \"efficiency=\",e*100,\"%\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "efficiency= 93.1001175389 %\n" + ] + } + ], + "prompt_number": 58 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example Number 31.14, Page Number:1104" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "#variable declaration\n", + "v=250.0#V\n", + "i=50.0#A\n", + "motor_i=400.0#A\n", + "i1=6.0#A\n", + "i2=5.0#A\n", + "ra=0.015#ohm\n", + "\n", + "#calculations\n", + "motora_culoss=motor_i**2*ra\n", + "generatora_culoss=(motor_i-i)**2*ra\n", + "power=v*i\n", + "stray_loss=power-(motora_culoss+generatora_culoss)\n", + "permachine=stray_loss/2\n", + "#motor\n", + "total_motor_loss=motora_culoss+(v*i2)+permachine\n", + "motor_input=(v*motor_i)+v*i2\n", + "motor_e=(motor_input-total_motor_loss)/motor_input\n", + "\n", + "#generator\n", + "total_gen_loss=generatora_culoss+(v*i1)+permachine\n", + "gen_output=v*(motor_i-i)\n", + "gen_e=(gen_output-total_gen_loss)/gen_output\n", + "\n", + "#result\n", + "print \"motor efficiency=\",motor_e*100,\"%\"\n", + "print \"generator efficiency\",gen_e*100,\"%\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "motor efficiency= 92.3148148148 %\n", + "generator efficiency 91.4642857143 %\n" + ] + } + ], + "prompt_number": 77 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example Number 31.15, Page Number:1105" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "#variable declaration\n", + "v=250.0#V\n", + "i=50.0#A\n", + "ia=380.0#A\n", + "i1=5.0#A\n", + "i2=4.2#A\n", + "ra=0.2#ohm\n", + "\n", + "#calculations\n", + "motora_culoss=ia**2*ra\n", + "generatora_culoss=(ia-i)**2*ra\n", + "power=v*i\n", + "stray_loss=power-(motora_culoss+generatora_culoss)\n", + "permachine=stray_loss/2\n", + "#motor\n", + "total_motor_loss=motora_culoss+(v*i2)+permachine\n", + "motor_input=(v*ia)+v*i2\n", + "motor_e=(motor_input-total_motor_loss)/motor_input\n", + "\n", + "#generator\n", + "total_gen_loss=generatora_culoss+(v*i1)+permachine\n", + "gen_output=v*(ia-i)\n", + "gen_e=(gen_output-total_gen_loss)/gen_output\n", + "\n", + "#result\n", + "print \"motor efficiency=\",motor_e*100,\"%\"\n", + "print \"generator efficiency\",gen_e*100,\"%\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "motor efficiency= 88.7038001041 %\n", + "generator efficiency 95.2121212121 %\n" + ] + } + ], + "prompt_number": 81 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example Number 31.16, Page Number:1107" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "#variable declaration\n", + "v=220.0#V\n", + "v2=190.0#V\n", + "t=30#sec\n", + "t2=20#sec\n", + "i=20.0#A\n", + "\n", + "#calculations\n", + "avg_v=(v+v2)/2\n", + "avg_i=i/2\n", + "power=avg_v*avg_i\n", + "W=power*(t2/(t-t2))\n", + "\n", + "#result\n", + "print \"Stray loss=\",W,\"W\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Stray loss= 4100.0 W\n" + ] + } + ], + "prompt_number": 85 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example Number 31.17, Page Number:1107" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "#variabledeclaration\n", + "n1=1525.0#rpm\n", + "n2=1475.0#ohm\n", + "dt=25.0#sec\n", + "p=1000.0#W\n", + "t2=20.0#sec\n", + "\n", + "#calculations\n", + "N=(n1+n2)/2\n", + "w=p*(t2/(dt-t2))\n", + "dN=n1-n2\n", + "I=(w*dt)/((2*3.14/60)**2*N*dN)\n", + "\n", + "#result\n", + "print \"Moment of Inertia=\",I,\"kg-m2\"\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Moment of Inertia= 121.708791432 kg-m2\n" + ] + } + ], + "prompt_number": 3 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example Number 31.18, Page Number:1108" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "#variable declaration\n", + "v=240.0#V\n", + "v2=225.0#V\n", + "dt=25.0#sec\n", + "t2=6.0#ohm\n", + "iavg=10.0#A\n", + "i2=25.0#A\n", + "v3=250.0#V\n", + "ra=0.4#ohm\n", + "r=250.0#ohm\n", + "\n", + "#calculations\n", + "avg_v=(v+v2)/2\n", + "w_=avg_v*iavg\n", + "W=w_*(t2/(dt-t2))\n", + "ish=v3/r\n", + "ia=i2-ish\n", + "cu_loss=ia**2*ra\n", + "cu_shunt=v3*ia\n", + "total_loss=W+cu_loss+v3\n", + "e=((v*i2)-total_loss)/(v*i2)\n", + "\n", + "#result\n", + "print \"efficiency=\",e*100,\"%\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "734.210526316\n", + "efficiency= 79.7564912281 %\n" + ] + } + ], + "prompt_number": 97 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example Number 31.19, Page Number:1108" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "#variable declaration\n", + "n=1000#rpm\n", + "n1=1030#rpm\n", + "n2=970#rpm\n", + "t1=36#sec\n", + "t2=15#sec\n", + "t3=9#sec\n", + "i=10#A\n", + "v=219#V\n", + "\n", + "#calculations\n", + "W=v*i*(t2/(dt-t2))\n", + "dN=n1-n2\n", + "I=(W*t2)/((2*3.14/60)**2*n*dN)\n", + "Wm=W*t2/t1\n", + "iron_loss=W-Wm\n", + "\n", + "#result\n", + "print \"i)moment of inertia=\",I,\"kg.m2\"\n", + "print \"ii)iron loss=\",iron_loss,\"W\"\n", + "print \"iii)mechanical losses=\",Wm,\"W\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "i)moment of inertia= 74.9650087225 kg.m2\n", + "ii)iron loss= 1916.25 W\n", + "iii)mechanical losses= 1368.75 W\n" + ] + } + ], + "prompt_number": 99 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example Number 31.20, Page Number:1110" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "#variable declaration\n", + "iam=56.0#A\n", + "vam=590.0#V\n", + "vdm=40.0#V\n", + "iag=44.0#A\n", + "vag=400.0#V\n", + "vdg=40.0#V\n", + "r=0.3#ohm\n", + "\n", + "#calculations\n", + "input_total=(vdm+vam)*iam\n", + "output=vag*iag\n", + "total_loss=input_total-output\n", + "rse=vdg/iam\n", + "cu_loss=((r+2*rse)*iam**2)+(iag**2*r)\n", + "strayloss=total_loss-cu_loss\n", + "permachine=strayloss/2\n", + "#motor\n", + "inputm=vam*iam\n", + "culossm=(r+rse)*iam**2\n", + "totallossm=culossm+permachine\n", + "output=inputm-totallossm\n", + "em=output*100/inputm\n", + "#generator\n", + "inputg=vag*iag\n", + "culossg=(r)*iag**2\n", + "totalloss=culossg+permachine+(vdm*iam)\n", + "output=vag*iag\n", + "eg=output*100/(output+totalloss)\n", + "\n", + "print \n", + "#result\n", + "print \"motor efficiency=\",em,\"%\"\n", + "print \"generator efficiency=\",eg,\"%\"\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "motor efficiency= 72.6997578692 %\n", + "generator efficiency= 67.0220868241 %\n" + ] + } + ], + "prompt_number": 115 + } + ], + "metadata": {} + } + ] +}
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