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| author | hardythe1 | 2015-06-03 15:27:17 +0530 |
|---|---|---|
| committer | hardythe1 | 2015-06-03 15:27:17 +0530 |
| commit | 47d7279a724246ef7aa0f5359cf417992ed04449 (patch) | |
| tree | c613e5e4813d846d24d67f46507a6a69d1a42d87 /Electronic_and_Electrical_Measuring_Instruments_&_Machines/Chapter9.ipynb | |
| parent | 435840cef00c596d9e608f9eb2d96f522ea8505a (diff) | |
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diff --git a/Electronic_and_Electrical_Measuring_Instruments_&_Machines/Chapter9.ipynb b/Electronic_and_Electrical_Measuring_Instruments_&_Machines/Chapter9.ipynb new file mode 100755 index 00000000..fda149db --- /dev/null +++ b/Electronic_and_Electrical_Measuring_Instruments_&_Machines/Chapter9.ipynb @@ -0,0 +1,1613 @@ +{
+ "cells": [
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "# Chapter 9 - D C Motors"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 1 - pg 9_14"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 3,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "e.m.f for lap wound (V) = 462.0\n",
+ "e.m.f for wave wound (V) = 924.0\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_1,pg 9_14\n",
+ "#calculate the emf for lap and wave wounds\n",
+ "#given\n",
+ "P=4.\n",
+ "Z=440.\n",
+ "phi=0.07#flux(in Wb)\n",
+ "N=900.\n",
+ "#for lap-wound\n",
+ "#calculations\n",
+ "A=P\n",
+ "E=phi*P*N*Z/(60*A)\n",
+ "#results\n",
+ "print\"e.m.f for lap wound (V) = \",E\n",
+ "#for wave wound\n",
+ "A=2.\n",
+ "E=phi*P*N*Z/(60*A)\n",
+ "print\"e.m.f for wave wound (V) = \",E\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 2 - pg 9_15"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 4,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "e.m.f for lap wound (V) = 263.424\n",
+ "speed of generator for wave wound (rpm) = 560.0\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_2,pg 9_15\n",
+ "#calculate the speed and emf\n",
+ "#given\n",
+ "P=4.\n",
+ "phi=21.*10**-3#flux(in Wb)\n",
+ "N=1120.\n",
+ "C=42.#coils\n",
+ "tpC=8.#turns per coil\n",
+ "#calculations and results\n",
+ "t=C*tpC#total turns\n",
+ "Z=2*t\n",
+ "#for lap wound\n",
+ "A=P\n",
+ "E=phi*P*N*Z/(60*A)\n",
+ "print\"e.m.f for lap wound (V) = \",E\n",
+ "#for wave wound\n",
+ "A=2.\n",
+ "E=263.424\n",
+ "N=E*60*A/(phi*P*Z)\n",
+ "print\"speed of generator for wave wound (rpm) = \",N"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 3 - pg 9_20"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 5,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "back e.m.f of motor (V) = 197.5\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_3,pg 9_20\n",
+ "#calculate the back emf \n",
+ "#given\n",
+ "V=220.\n",
+ "Ia=30.\n",
+ "Ra=0.75\n",
+ "#calculations\n",
+ "Eb=V-Ia*Ra\n",
+ "#results\n",
+ "print\"back e.m.f of motor (V) = \",Eb\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 4 - pg 9_21"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 6,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "back e.m.f (V) = 206.0\n",
+ "speed of motor (rpm) = 1648.0\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_4,pg 9_21\n",
+ "#calculate the back emf and speed of motor\n",
+ "P=4.\n",
+ "A=P\n",
+ "V=230.\n",
+ "Ra=0.6\n",
+ "Z=250.\n",
+ "phi=30.*10**-3#flux(in Wb)\n",
+ "Ia=40.\n",
+ "#calculations\n",
+ "Eb=V-Ia*Ra\n",
+ "N=Eb*60*A/(phi*P*Z)\n",
+ "#results\n",
+ "print\"back e.m.f (V) = \",Eb\n",
+ "print\"speed of motor (rpm) = \",N\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 5 - pg 9_24"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 7,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "gross torque (N-m) = 76.32\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_5,pg 9_24\n",
+ "#calculate the gross torque\n",
+ "#given\n",
+ "P=4.\n",
+ "A=P\n",
+ "Z=480.\n",
+ "phi=20.*10**-3#flux(in Wb)\n",
+ "Ia=50.\n",
+ "#calculations\n",
+ "Ta=0.159*phi*Ia*(P*Z/A)\n",
+ "#results\n",
+ "print\"gross torque (N-m) = \",Ta"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 6 - pg 9_25"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 8,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "induced e.m.f (V) = 225.0\n",
+ "armature current (A) = 6.25\n",
+ "stray losses (W) = 1406.25\n",
+ "loss torque (Nm) = 13.429\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_6,pg 9_25\n",
+ "#calculate the induced emf, armature current, stray losses and loss torque\n",
+ "import math\n",
+ "#given\n",
+ "P=4.\n",
+ "A=P\n",
+ "No=1000.#speed of motor\n",
+ "Z=540.\n",
+ "V=230.\n",
+ "phi=25.*10**-3#flux(In Wb)\n",
+ "Ra=0.8\n",
+ "#calculations\n",
+ "Ebo=phi*P*No*Z/(60*A)#induced e.m.f\n",
+ "Iao=(V-Ebo)/Ra#armature current\n",
+ "SL=Ebo*Iao#stray losses\n",
+ "wo=2*math.pi*No/60#angular velocity\n",
+ "Tf=Ebo*Iao/wo#loss torque\n",
+ "#results\n",
+ "print\"induced e.m.f (V) = \",Ebo\n",
+ "print\"armature current (A) = \",Iao\n",
+ "print\"stray losses (W) = \",SL\n",
+ "print\"loss torque (Nm) = \",round(Tf,3)\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 7 - pg 9_37"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 9,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "speed of motor (rpm) = 1374.0\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_7,pg 9_37\n",
+ "#calculate the speed of motor\n",
+ "#given\n",
+ "P=4.\n",
+ "Z=200.\n",
+ "V=250.\n",
+ "A=2.\n",
+ "phi=25.*10**-3\n",
+ "Ia=60.\n",
+ "#calculations\n",
+ "Il=Ia\n",
+ "Ra=0.15\n",
+ "Rse=0.2\n",
+ "Eb=V-Ia*(Ra+Rse)\n",
+ "N=Eb*60*A/(phi*P*Z)\n",
+ "#results\n",
+ "print\"speed of motor (rpm) = \",N\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 8 - pg 9_38"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 10,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "back e.m.f (V) = 244.375\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_8,pg 9_38\n",
+ "#calculate the back emf\n",
+ "#given\n",
+ "V=250.\n",
+ "Il=20.\n",
+ "Ra=0.3\n",
+ "Rsh=200.\n",
+ "#calculations\n",
+ "Ish=V/Rsh\n",
+ "Ia=Il-Ish\n",
+ "Eb=V-Ia*Ra\n",
+ "#results\n",
+ "print\"back e.m.f (V) = \",Eb\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 9 - pg 9_38"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 11,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "speed at full load (rpm) = 939.67\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_9,pg 9_38\n",
+ "#calculate the speed at full load\n",
+ "#given\n",
+ "No=1000.\n",
+ "V=220.\n",
+ "Rsh=110.\n",
+ "Ra=0.3\n",
+ "#calculations\n",
+ "Ish=V/Rsh\n",
+ "Ilo=6.\n",
+ "Iao=Ilo-Ish\n",
+ "Rao=0.3\n",
+ "Ebo=V-Iao*Ra\n",
+ "#on full load\n",
+ "Il=50\n",
+ "IaFL=Il-Ish\n",
+ "EbFL=V-IaFL*Ra\n",
+ "#N=k*Eb/phi\n",
+ "NFL=No*EbFL/Ebo\n",
+ "#results\n",
+ "print\"speed at full load (rpm) = \",round(NFL,2)\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 10 - pg 9_39"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 12,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "speed of motor on new load (rpm) = 300.0\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_10,pg 9_39\n",
+ "#calculate the speed of motor on new load\n",
+ "#given\n",
+ "N1=800.\n",
+ "I1=20.\n",
+ "V=250.\n",
+ "Ia1=I1\n",
+ "I2=50.\n",
+ "Ia2=I2\n",
+ "Ra=0.2\n",
+ "Ise1=I1\n",
+ "Ise2=I2\n",
+ "Rse=0.3\n",
+ "#calculations\n",
+ "Eb1=V-Ia1*Ra-Ise1*Rse\n",
+ "Eb2=V-Ia2*Ra-Ise2*Rse\n",
+ "#from speed equation\n",
+ "N2=N1*(Eb2/Eb1)*(Ia1/Ia2)\n",
+ "#results\n",
+ "print\"speed of motor on new load (rpm) = \",N2\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 11 - pg 9_45"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 13,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "new current (A) = 40.0\n",
+ "new speed (rpm) = 2938.776\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_11,pg 9_45\n",
+ "#calculate the new current and speed\n",
+ "#given\n",
+ "V=250.\n",
+ "Rsh=250.\n",
+ "Ra=0.25\n",
+ "Rx=Rsh\n",
+ "Ia1=20.\n",
+ "#calculations\n",
+ "Ish1=V/Rsh\n",
+ "Ish2=V/(Rsh+Rx)\n",
+ "N1=1500.\n",
+ "Eb1=V-Ia1*Ra\n",
+ "#phi=k*Ish\n",
+ "#T1=T2\n",
+ "Ia2=Ish1*Ia1/Ish2#new current\n",
+ "Eb2=V-Ia2*Ra\n",
+ "#from speed equation\n",
+ "N2=N1*(((Eb1/Eb2)*(Ish2/Ish1))**-1)#new speed\n",
+ "#results\n",
+ "print\"new current (A) = \",Ia2\n",
+ "print\"new speed (rpm) = \",round(N2,3)\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 12 - pg 9_46"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 14,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "resistance in shunt field (ohm) = 88.313\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_12,pg 9_46\n",
+ "#calculate the resistance in shunt field\n",
+ "#given\n",
+ "import math\n",
+ "V=250.\n",
+ "Ra=0.5\n",
+ "Rsh=250.\n",
+ "Ia1=20.\n",
+ "Ish1=V/Rsh\n",
+ "Eb1=V-Ia1*Ra\n",
+ "N1=600.\n",
+ "N2=800.\n",
+ "#T1=T2\n",
+ "#Ish1*Ia1=Ish2*Ia2\n",
+ "#Ish2*Ia2=20............(1)\n",
+ "#(N1/N2)=(Eb1/Eb2)*(Ish2/Ish1)...........(2)\n",
+ "#using (1) and (2)\n",
+ "#240*(Ish2^2)-187.5*Ish2+7.5=0.........(3)\n",
+ "b=-187.5\n",
+ "a=240\n",
+ "c=7.5\n",
+ "#calculations\n",
+ "Ish2=(-b+math.sqrt(((b**2)-4*a*c)))/(2*a)#neglecting lower value\n",
+ "Rx=(V/Ish2)-Rsh\n",
+ "#results\n",
+ "print\"resistance in shunt field (ohm) = \",round(Rx,3)\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 13 - pg 9_51"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 15,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "speed of motor (rpm) = 912.743\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_13,pg 9_51\n",
+ "#calculate the speed of motor\n",
+ "#given\n",
+ "import math\n",
+ "V=250.\n",
+ "Ra=0.15\n",
+ "Rx=0.1\n",
+ "Rse=0.1\n",
+ "N1=800.\n",
+ "Ise1=30.\n",
+ "Ia1=30.#Ia1=Ise1\n",
+ "I1=Ia1\n",
+ "#phi=k*Ise\n",
+ "#T2=T1+0.5*T1(increased by 50%)..........(1)\n",
+ "#Ise2=Ia2*Rx/(Rx+Rse)\n",
+ "#putting values of Rx and Rse Ise2=0.5*Ia2.........(2)\n",
+ "#putting (1) and (2) in torque equation\n",
+ "#calculations\n",
+ "Ia2=math.sqrt(2700)\n",
+ "Ise2=0.5*Ia2#from (2)\n",
+ "Eb1=V-Ia1*Ra-Ise1*Rse\n",
+ "Eb2=V-Ia2*Ra-Ise2*Rse\n",
+ "#using speed equation\n",
+ "N2=N1*Eb2*Ise1/(Eb1*Ise2)\n",
+ "#results\n",
+ "print\"speed of motor (rpm) = \",round(N2,3)\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 14 - pg 9_52"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 16,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "speed of motor (rpm) = 1119.5122\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_14,pg 9_52\n",
+ "#calculate the speed of motor\n",
+ "#given\n",
+ "V=220.\n",
+ "Ise1=15.\n",
+ "Ia1=Ise1\n",
+ "Ia2=10.\n",
+ "Ise2=Ia2\n",
+ "I2=Ia2\n",
+ "N1=900.\n",
+ "Ra=0.5\n",
+ "Rse=0.5\n",
+ "Rx=4.\n",
+ "#calculations\n",
+ "Eb1=V-Ia1*Ra-Ise1*Rse\n",
+ "Eb2=V-Ia2*Ra-Ise2*Rse-I2*Rx\n",
+ "N2=N1*Eb2*Ise1/(Eb1*Ise2)\n",
+ "#results\n",
+ "print\"speed of motor (rpm) = \",round(N2,4)\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 15 - pg 9_64"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 18,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "useful torque (Nm) = 185.26\n",
+ "efficiency at load (percent) = 79.38\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_15,pg 9_64\n",
+ "#calculate the useful torque and efficiency at load\n",
+ "#given\n",
+ "import math\n",
+ "P=6.\n",
+ "V=500.\n",
+ "A=2.#wave wound\n",
+ "Z=1200.\n",
+ "phi=20*10**-3#flux\n",
+ "Ra=0.5\n",
+ "Rsh=250.\n",
+ "Il=20.\n",
+ "#calculations\n",
+ "Ish=V/Rsh\n",
+ "Ia=Il-Ish\n",
+ "Eb=V-Ia*Ra\n",
+ "N=Eb*60*A/(phi*P*Z)\n",
+ "Pm=Eb*Ia#mechanical power\n",
+ "w=2*math.pi*N/60#angular velocity\n",
+ "Tg=Pm/w\n",
+ "ML=900#mechanical losses\n",
+ "Pout=Pm-ML\n",
+ "Tsh=Pout/w#usefull torque\n",
+ "Pin=V*Il\n",
+ "n=Pout*100/Pin#efficiency at load\n",
+ "#results\n",
+ "print\"useful torque (Nm) = \",round(Tsh,2)\n",
+ "print\"efficiency at load (percent) = \",n\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 16 - pg 9_65"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 19,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "speed of motor (rpm) = 1860.85\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_16,pg 9_65\n",
+ "#calculate the speed of motor\n",
+ "#given\n",
+ "V=120.\n",
+ "Ra=0.2\n",
+ "Rsh=60.\n",
+ "#for full load\n",
+ "Il1=40.\n",
+ "N1=1800.\n",
+ "#for shunt motor\n",
+ "#calculations\n",
+ "Ish=V/Rsh\n",
+ "Ia1=Il1-Ish\n",
+ "Eb1=V-Ia1*Ra\n",
+ "#for half load T2=T1/2\n",
+ "Ia2=Ia1*0.5#T=k*Ia\n",
+ "Eb2=V-Ia2*Ra\n",
+ "N2=N1*Eb2/Eb1#from torque equation\n",
+ "#results\n",
+ "print\"speed of motor (rpm) = \",round(N2,2)\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 17 - pg 9_66"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 21,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "speed as generator (rpm) = 1592.7\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_17,pg 9_66\n",
+ "#calculate the speed of generator\n",
+ "#given\n",
+ "Ra=0.08\n",
+ "Eb1=242.\n",
+ "V=250.\n",
+ "Ia=87.\n",
+ "Vt=V#generator supply\n",
+ "Nm=1500.\n",
+ "#calculations\n",
+ "Ia1=(V-Eb1)/Ra\n",
+ "#at start N=0, Eb=0\n",
+ "Ias=V/Ra#Ia(start)\n",
+ "Ia2=120\n",
+ "Eb2=V-Ia2*Ra\n",
+ "Eg=Vt+Ia*Ra#generator e.m.f\n",
+ "Ng=Nm*Eg/Eb1#speed as generator\n",
+ "#results\n",
+ "print\"speed as generator (rpm) = \",round(Ng,1)"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 18 - pg 9_67"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 22,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "gross mechanical power (kW) = 70.812\n",
+ "stray losses (W) = 11132.13\n",
+ "no load speed (rpm) = 1250.9121\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_18,pg 9_67\n",
+ "#calculate the gross mechanical power,stray losses and no load speed\n",
+ "#given\n",
+ "import math\n",
+ "V=250.\n",
+ "Po=59680.\n",
+ "Rsh=250.\n",
+ "Ra=0.04\n",
+ "n=80.#efficiency\n",
+ "N1=1200.\n",
+ "#calculations and results\n",
+ "Il=Po*100/(V*n)#Pi=V*Il\n",
+ "Ish=V/Rsh\n",
+ "Ia=Il-Ish\n",
+ "Eb=V-Ia*Ra\n",
+ "Pm=Eb*Ia#gross mechanical power\n",
+ "SL=Pm-Po#stray losses\n",
+ "print\"gross mechanical power (kW) = \",round(Pm/1000.,3)\n",
+ "print\"stray losses (W) = \",round(SL,2)\n",
+ "#on no load\n",
+ "#Pg=S, Ebo*Iao=SL..........(1)\n",
+ "#Ebo=V-Iao*Ra............(2)\n",
+ "#putting (2) in (1)\n",
+ "#(Iao^2)-6250*Iao+278303.24=0\n",
+ "b=-6250.\n",
+ "a=1.\n",
+ "c=278303.24\n",
+ "Iao=(-b-math.sqrt((b**2)-4*a*c))/(2*a)\n",
+ "I=Iao-Ish#current drawn on no load\n",
+ "Ebo=V-Iao*Ra\n",
+ "No=N1*Ebo/Eb\n",
+ "print\"no load speed (rpm) = \",round(No,4)\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 19 - pg 9_69"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 23,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "full load speed (rpm) = 1234.102\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_19,pg 9_69\n",
+ "#calculate the full load speed\n",
+ "#given\n",
+ "V=250.\n",
+ "P=4.\n",
+ "Ra=0.1\n",
+ "Rsh=125.\n",
+ "Vbr=2.#brush drop\n",
+ "#no load condition\n",
+ "Ilo=4.\n",
+ "No=1200.\n",
+ "Il1=61.\n",
+ "#calculations\n",
+ "Ish=V/Rsh\n",
+ "Iao=Ilo-Ish\n",
+ "Ebo=V-Iao*Ra-Vbr\n",
+ "#full load condition\n",
+ "#phi1=phio-o.o5*phio (weakened by 5%)\n",
+ "#phi=phi1/phio\n",
+ "phi=0.95\n",
+ "Ia1=Il1-Ish\n",
+ "Eb1=V-Ia1*Ra-Vbr\n",
+ "N1=No*Eb1/(Ebo*phi)\n",
+ "#results\n",
+ "print\"full load speed (rpm) = \",round(N1,3)\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 20 - pg 9_70"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 24,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "full load speed (rpm) = 1233.396\n",
+ "speed regulation (percent) = 3.64\n",
+ "hp rating of machine (hp) = 19.42\n",
+ "full load efficiency (percent) = 86.48\n",
+ "The answer differs from the textbook due to rounding off error\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_20,pg 9_70\n",
+ "#calculate the full load speed, speed regulation, hp rating and efficiency\n",
+ "#given\n",
+ "V=250.\n",
+ "Ra=0.15\n",
+ "Rsh=166.67\n",
+ "No=1280.\n",
+ "Il1=67.\n",
+ "#calculations\n",
+ "Ish=V/Rsh\n",
+ "Ia1=Il1-Ish\n",
+ "Eb1=V-Ia1*Ra\n",
+ "#on no load\n",
+ "Ilo=6.5\n",
+ "Ish=1.5\n",
+ "Iao=Ilo-Ish\n",
+ "Ebo=V-Iao*Ra\n",
+ "N1=Eb1*No/Ebo\n",
+ "Sr=(No-N1)*100/No#speed regulation\n",
+ "SL=Ebo*Iao\n",
+ "Po=Eb1*Ia1-SL#full load shaft output\n",
+ "hp=Po/746.#horse power rating\n",
+ "Pi=V*Il1\n",
+ "n=Po*100./Pi\n",
+ "#results\n",
+ "print\"full load speed (rpm) = \",round(N1,3)\n",
+ "print\"speed regulation (percent) = \",round(Sr,2)\n",
+ "print\"hp rating of machine (hp) = \",round(hp,2)\n",
+ "print\"full load efficiency (percent) = \",round(n,2)\n",
+ "print \"The answer differs from the textbook due to rounding off error\""
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 21 - pg 9_71"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 25,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "speed of motor (rpm) = 976.389\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_21,pg 9_71\n",
+ "#calculate the speed of motor\n",
+ "import math\n",
+ "#given\n",
+ "Ra=0.1\n",
+ "V=110.\n",
+ "P=4.\n",
+ "Ia1=50.\n",
+ "I1=Ia1\n",
+ "Rse=0.02\n",
+ "N1=700\n",
+ "#calculations\n",
+ "Eb1=V-Ia1*Ra-Ia1*Rse\n",
+ "#using torque equation T=k*phi*Ia\n",
+ "Ia2=math.sqrt(2)*Ia1\n",
+ "Eb2=V-Ia2*Ra-Ia2*Rse/4#parallel speed groups\n",
+ "#using speed equation N=k*Eb/phi\n",
+ "N2=N1*Eb2*2*Ia1/(Eb1*Ia2)\n",
+ "#results\n",
+ "print\"speed of motor (rpm) = \",round(N2,3)\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 22 - pg 9_73"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 26,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "new speed of motor (rpm) = 2378.414\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_22,pg 9_73\n",
+ "#calculate the new speed of motor\n",
+ "#given\n",
+ "P=4.\n",
+ "Ia1=50.\n",
+ "N1=2000.\n",
+ "V=230.\n",
+ "#calculations\n",
+ "#coils connected in series\n",
+ "#phi1=k*Ia1*(4*n)=k*200*n\n",
+ "#coils connected in parallel groups of series coils\n",
+ "#phi2=k*((Ia2*2*n/2)+(Ia2*2*n/2))=k*2*n*Ia2\n",
+ "#phi1/phi2=100/Ia2........(1)\n",
+ "#N1/N2=phi2/phi1........(2)\n",
+ "#T=kN**2..........(3)\n",
+ "Ia2=(Ia1*(100**3))**(1./4)#using (1) in (3)\n",
+ "N2=(((N1**3)*Ia2)/Ia1)**(1./3)\n",
+ "#results\n",
+ "print\"new speed of motor (rpm) = \",round(N2,3)\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 24 - pg 9_76"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 27,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "extra resistance to reduce speed (ohm) = 9.744\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_24,pg 9_76\n",
+ "#calculate the extra resistance to reduce speed\n",
+ "import math\n",
+ "#given\n",
+ "V=200.\n",
+ "Ia1=30.\n",
+ "Ra=0.75\n",
+ "Rse=0.75\n",
+ "#calculations\n",
+ "R=Ra+Rse\n",
+ "Eb1=V-Ia1*R\n",
+ "#N2=0.6*N1\n",
+ "N=0.6#N=N2/N1\n",
+ "#using T=k*Ia**2 and T=k*N**3\n",
+ "Ia2=math.sqrt(((0.6**3)*30**2))\n",
+ "#using speed equation N=k*Eb/Ia\n",
+ "Eb2=N*Eb1*Ia2/Ia1\n",
+ "#Eb2=V-Ia2*(R+Rx)\n",
+ "Rx=-(Eb2-V+Ia2*R)/Ia2\n",
+ "#results\n",
+ "print\"extra resistance to reduce speed (ohm) = \",round(Rx,3)\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 25 - pg 9_77"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 28,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "new supply voltage (V) = 354.6875\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_25,pg 9_77\n",
+ "#calculate the new supply voltage\n",
+ "#given\n",
+ "R=1.\n",
+ "V1=230.\n",
+ "N1=300.\n",
+ "Ia1=15.\n",
+ "N2=375.\n",
+ "#calculations\n",
+ "#using torque equation T=k*N^2\n",
+ "Ia2=N2*Ia1/N1\n",
+ "#using speed equation N=k*Eb/Ia........(1)\n",
+ "Eb1=V1-Ia1*R\n",
+ "#case-2\n",
+ "#Eb2=V2-Ia2*R=V2-18.75......(2)\n",
+ "#putting (2) in (1)\n",
+ "V2=(N2*Eb1*Ia2/(N1*Ia1))+18.75\n",
+ "#results\n",
+ "print\"new supply voltage (V) = \",V2\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 26 - pg 9_78"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 29,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "power input in case-2 (kW) = 12.145\n",
+ "efficiency of motor = 74.107\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_26,pg 9_78\n",
+ "#calculate the power input and efficiency of motor\n",
+ "#given\n",
+ "import math\n",
+ "V=400.\n",
+ "Po1=18.5*10**3\n",
+ "Pi1=22.5*10**3\n",
+ "Rsh=200.\n",
+ "Ra=0.4\n",
+ "Po2=9.*10**3\n",
+ "#calculations\n",
+ "I1=Pi1/V\n",
+ "Ish=V/Rsh\n",
+ "Ia1=I1-Ish\n",
+ "Acl=(Ia1**2)*Ra#armature copper loss\n",
+ "Scl=(Ish**2)*Rsh#shunt feild copper loss\n",
+ "TL=Pi1-Po1#total losses\n",
+ "SFl=TL-(Acl+Scl)#stray and friction loss\n",
+ "#case-2\n",
+ "Pm=Po2+SFl#mechanical power\n",
+ "#Pm=Eb2*Ia2.........(1)\n",
+ "#Eb2=V-Ia2*Ra.......(2)\n",
+ "#using (1) and (2)\n",
+ "#0.4*(Ia2**2)-400*Ia2+11022.75=0\n",
+ "a=0.4\n",
+ "b=-400\n",
+ "c=11022.775\n",
+ "Ia2=(-b-math.sqrt((b**2)-4*a*c))/(2*a)#neglecting higher value\n",
+ "Pi2=Po2+(Ia2**2)*Ra+(Ish**2)*Rsh+SFl\n",
+ "n=Po2*100/Pi2#efficiency\n",
+ "#results\n",
+ "print\"power input in case-2 (kW) = \",round(Pi2/1000.,3)\n",
+ "print\"efficiency of motor = \",round(n,3)\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 27 - pg 9_79"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 30,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "maximum efficiency = 75.59\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_27,pg 9_79\n",
+ "#calculate the maximum efficiency\n",
+ "#given\n",
+ "import math\n",
+ "V=250.\n",
+ "Ilo=4.\n",
+ "Ra=1.\n",
+ "Rsh=250.\n",
+ "Il1=20.\n",
+ "#calculations\n",
+ "Ish=V/Rsh\n",
+ "Iao=Ilo-Ish\n",
+ "Ia1=Il1-Ish\n",
+ "Ebo=V-Iao*Ra\n",
+ "Po=Ebo*Iao\n",
+ "Eb1=V-Ia1*Ra\n",
+ "P1=Eb1*Ia1\n",
+ "Pout=P1-Po\n",
+ "Pi=V*Il1\n",
+ "n=Pout*100/Pi\n",
+ "#fro max. efficiency\n",
+ "#const. losses=variable losses\n",
+ "Ia=math.sqrt(Po+(Ish**2)*Rsh)\n",
+ "Ebm=V-Ia*Ra\n",
+ "Pm=Ebm*Ia\n",
+ "Pout=Pm-Po\n",
+ "Pi=V*(Ia+Ish)\n",
+ "nm=Pout*100/Pi\n",
+ "#results\n",
+ "print\"maximum efficiency = \",round(nm,2)\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 28 - pg 9_81"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 31,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "back e.m.f (V) = 83.33\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_28,pg 9_81\n",
+ "#calculate the back emf\n",
+ "#given\n",
+ "V=250.\n",
+ "FLo=16.*10**3#full scale output\n",
+ "n=80.\n",
+ "#calculations\n",
+ "I=FLo*100/n#input\n",
+ "Il=I/V\n",
+ "Il=Il\n",
+ "Ia=1.5*Il\n",
+ "#at start\n",
+ "Ra=V/Ia\n",
+ "Rac=0.18#Ra actual\n",
+ "Ras=Ra-Rac#Ra starter\n",
+ "Ia=Il#Ia drops as motor starts\n",
+ "Eb=V-Ia*(Ra)\n",
+ "#results\n",
+ "print\"back e.m.f (V) = \",round(Eb,2)\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 29 - pg 9_82"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 33,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "electromagnetic torque (Nm) = 122.148\n",
+ "flux per pole (mWb) = 11.9316\n",
+ "efficiency of motor (percent) = 85.733\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_29,pg 9_82\n",
+ "#calculate the electromagnetic torque, flux and efficiency\n",
+ "#given\n",
+ "import math\n",
+ "Po=20.*735.5#(in W)\n",
+ "V=230.\n",
+ "N=1150.\n",
+ "P=4.\n",
+ "A=P\n",
+ "Z=882.\n",
+ "Ia=73.\n",
+ "Ish=1.6\n",
+ "#calculations\n",
+ "T=60*Po/(2*math.pi*N)\n",
+ "phi=T*A/(0.159*Ia*P*Z)#flux per pole\n",
+ "Il=Ia+Ish\n",
+ "Pin=V*Il\n",
+ "n=Po*100/Pin\n",
+ "#results\n",
+ "print\"electromagnetic torque (Nm) = \",round(T,4)\n",
+ "print\"flux per pole (mWb) = \",round(phi*1000.,4)\n",
+ "print\"efficiency of motor (percent) = \",round(n,3)"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 30 - pg 9_83"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 34,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "speed of motor (rpm) = 785.478\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_30,pg 9_83\n",
+ "#calculate the speed of motor\n",
+ "#given\n",
+ "Pr=12.*10**3#rated output\n",
+ "V=200.\n",
+ "Rsh=80.\n",
+ "N1=800.\n",
+ "n=0.9#efficiency\n",
+ "#calculations\n",
+ "Out=0.8*Pr#output is 80% of rated\n",
+ "In=Out/n#input\n",
+ "TL=In-Out\n",
+ "#for max. efficiency\n",
+ "Iln=70#new current\n",
+ "#TL=Wc+(Ia1^2)*Ra\n",
+ "#bur Wc=(Ia1^2)*Ra\n",
+ "Wc=TL/2\n",
+ "Il=In/V\n",
+ "Ish=V/Rsh\n",
+ "Ia1=Il-Ish\n",
+ "Ra=Wc/(Ia1**2)\n",
+ "Ia2=Iln-Ish\n",
+ "Wcn=Wc#const. losses remain same\n",
+ "TL=(Ia2**2)*Ra+Wcn\n",
+ "Pi=V*Iln\n",
+ "n=(Pi-TL)*100/Pi\n",
+ "Eb1=V-Ia1*Ra\n",
+ "Eb2=V-Ia2*Ra\n",
+ "N2=N1*Eb2/Eb1\n",
+ "#results\n",
+ "print\"speed of motor (rpm) = \",round(N2,3)\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 31 - pg 9_85"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 35,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "efficiency of motor (percent) = 84.896\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_31,pg 9_85\n",
+ "#calculate the efficiency of motor\n",
+ "#given\n",
+ "Po=8.952*10**3\n",
+ "V=440.\n",
+ "Ra=1.1\n",
+ "Rsh=650\n",
+ "Rint=0.4\n",
+ "Rreg=50.\n",
+ "Ml=450.\n",
+ "Vbr=2.#brush drop\n",
+ "Il=24.\n",
+ "#calculations\n",
+ "Rat=Ra+Rint#series connection\n",
+ "Rsht=Rsh+Rreg#series connection\n",
+ "Ish=V/Rsht\n",
+ "Ia=Il-Ish\n",
+ "Acl=(Ia**2)*Rat#armature copper loss\n",
+ "Fcl=(Ish**2)*Rsht#feild copper loss\n",
+ "Bdl=Vbr*Ia#brush drop loss\n",
+ "TL=Acl+Fcl+Bdl+Ml\n",
+ "n=Po*100/(Po+TL)\n",
+ "#results\n",
+ "print\"efficiency of motor (percent) = \",round(n,3)\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 32 - pg 9_85"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 36,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "speed of motors (rpm) = 334.816\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_32,pg 9_85\n",
+ "#calculate the speed of motors\n",
+ "#given\n",
+ "#for first motor\n",
+ "N1=700.\n",
+ "R=0.5#Ra+Rse\n",
+ "I1=70.\n",
+ "V=500.\n",
+ "#calculations\n",
+ "Eb1=V-I1*R\n",
+ "K1=Eb1/(N1*I1)\n",
+ "#for second motor\n",
+ "N2=750.\n",
+ "R=0.5\n",
+ "I2=70.\n",
+ "V=500.\n",
+ "Eb2=V-I2*R\n",
+ "K2=Eb2/(N2*I2)\n",
+ "#motors in series\n",
+ "It=70.\n",
+ "Rt=2*R\n",
+ "Eb=V-It*Rt\n",
+ "N=Eb/(K1*It+K2*It)\n",
+ "#results\n",
+ "print\"speed of motors (rpm) = \",round(N,3)\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 33 - pg 9_86"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 37,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "maximum efficiency output (W) = 10225.936\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_33,pg 9_86\n",
+ "#calculate the maximum efficiency output\n",
+ "#given\n",
+ "import math\n",
+ "Po=7.46*10**3\n",
+ "V=250\n",
+ "Ilo=5.\n",
+ "Ra=0.5\n",
+ "Rsh=250.\n",
+ "#calculations\n",
+ "Ish=V/Rsh\n",
+ "Iao=Ilo-Ish\n",
+ "Acl=(Iao**2)*Ra\n",
+ "Fcl=(Ish**2)*Rsh\n",
+ "Pi=V*Ilo\n",
+ "FWl=Pi-Acl-Fcl#friction and windage loss\n",
+ "#Pin=Eb*Ia=(V-Ia*Ra)*Ia\n",
+ "#0.5*(Ia**2)-250*Ia+8452=0\n",
+ "b=-250\n",
+ "a=0.5\n",
+ "c=8452\n",
+ "Ia=(-b-math.sqrt((b**2)-4*a*c))/(2*a)#neglecting higher value\n",
+ "TL=(Ia**2)*Ra+(Ish**2)*Rsh+FWl\n",
+ "n=Po*100/(Po+TL)\n",
+ "#for max. efficiency\n",
+ "Ia=math.sqrt((FWl+Fcl)/Ra)\n",
+ "Eb=V-Ia*Ra\n",
+ "Pm=Eb*Ia\n",
+ "#Po at nmax\n",
+ "Po=Pm-FWl\n",
+ "#results\n",
+ "print\"maximum efficiency output (W) = \",round(Po,3)\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Example 34 - pg 9_87"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 38,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "speed of motor case-1 (rpm) = 946.817\n",
+ "speed of motor case-2 (rpm) = 830.983\n",
+ "speed of motor case-3 (rpm) = 1101.3554\n"
+ ]
+ }
+ ],
+ "source": [
+ "#Chapter-9,Example9_33,pg 9_87\n",
+ "#calculate the speed of motor in both cases\n",
+ "#given\n",
+ "V=500.\n",
+ "Ra=1.2\n",
+ "Rsh=500.\n",
+ "#calculations\n",
+ "Ish=V/Rsh\n",
+ "Ilo=4.\n",
+ "Iao=Ilo-Ish\n",
+ "Ebo=V-Iao*Ra\n",
+ "Il1=26.\n",
+ "Ish1=1.\n",
+ "Ia1=Il1-Ish1\n",
+ "Eb1=V-Ia1*Ra\n",
+ "No=1000.\n",
+ "N1=No*Eb1/Ebo\n",
+ "print\"speed of motor case-1 (rpm) = \",round(N1,3)\n",
+ "Rx=2.3#connected in series with armature\n",
+ "Eb2=V-Ia1*(Ra+Rx)\n",
+ "N2=N1*Eb2/Eb1\n",
+ "#results\n",
+ "print\"speed of motor case-2 (rpm) = \",round(N2,3)\n",
+ "Ish3=Ish1-0.15*Ish1#reduced by 15%\n",
+ "Ia3=Ish1*Ia1/(Ish3)\n",
+ "Eb3=V-Ia3*Ra\n",
+ "N3=N1*Eb3*Ish1/(Eb1*Ish3)\n",
+ "print\"speed of motor case-3 (rpm) = \",round(N3,4)\n"
+ ]
+ }
+ ],
+ "metadata": {
+ "kernelspec": {
+ "display_name": "Python 2",
+ "language": "python",
+ "name": "python2"
+ },
+ "language_info": {
+ "codemirror_mode": {
+ "name": "ipython",
+ "version": 2
+ },
+ "file_extension": ".py",
+ "mimetype": "text/x-python",
+ "name": "python",
+ "nbconvert_exporter": "python",
+ "pygments_lexer": "ipython2",
+ "version": "2.7.9"
+ }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
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