{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 9: Power Conversation and Motor Drive Operations" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Example 9.1,Page 457" ] }, { "cell_type": "code", "execution_count": 1, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "peak voltage is 37.6 V\n", "load voltage is 35.7 V\n", "ripple voltage is 3.96 V\n", "approx. load voltage is 35.62 V\n" ] } ], "source": [ "#finding peak,load,ripple voltages\n", "\n", "#initialisation of variable\n", "from math import pi,tan,sqrt,sin,cos,acos,atan\n", "V=28.0;#V\n", "C=4700.0;#microF\n", "R=16.0;#load\n", "f=120.0;#hertz\n", "\n", "#calculation\n", "Vp=V*2**.5-2;\n", "Vd=0.95*Vp;\n", "Id=Vd/R;\n", "v=Id/f/C;\n", "#approximation\n", "Vd1=Vp-v*1e6/2;\n", "\n", "#result\n", "print \"peak voltage is\",round(Vp,2), \"V\"\n", "print \"load voltage is\",round(Vd,1), \"V\"\n", "print \"ripple voltage is\",round(v*1e6,2), \"V\"\n", "print \"approx. load voltage is\",round(Vd1,2), \"V\"" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 9.2,Page 459" ] }, { "cell_type": "code", "execution_count": 2, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Zth is 1.0 + 1.0 in ohm\n", "inductor is 2.65 mH\n" ] } ], "source": [ "#finding inductor,Zth\n", "\n", "#initialisation of variable\n", "from math import pi,tan,sqrt,sin,cos,acos,atan\n", "V1=120.0;#pri voltage\n", "V2=28.0;#sec voltage\n", "I=2.0;#pri current\n", "f=60.0;#Hz\n", "Vth=28.8;#open voltage\n", "V3=12.1;#pri-short voltage\n", "Is=2.0;#short current at 45 degree\n", "\n", "#calculation\n", "Zi=(V2*V3)/V1/Is*cos(45*pi/180);\n", "Zj=(V2*V3)/V1/Is*sin(45*pi/180);\n", "L=Zi/(2*pi*f);\n", "\n", "#result\n", "print'Zth is',round(Zi),'+',round(Zj),'in ohm'\n", "print \"inductor is\",round(L*1000,2), \"mH\"" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Example 9.4,Page 463" ] }, { "cell_type": "code", "execution_count": 3, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "power factor is 0.32\n" ] } ], "source": [ "#finding power factor\n", "\n", "#initialisation of variable\n", "from math import pi,tan,sqrt,sin,cos,acos,atan\n", "I1=1.8;#current\n", "R=16.0;#resistance\n", "I2=5.7;#A\n", "V=28.8;#Voltage\n", "\n", "#calculation\n", "P=I1**2*R;\n", "S=I2*V;\n", "Pf=P/S;\n", "\n", "#result\n", "print \"power factor is\",round(Pf,2)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Example 9.5, Page 468" ] }, { "cell_type": "code", "execution_count": 2, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "aparrent power is 8.14 kVA\n", "dissipated power is 7.84 kW\n", "power factor is 0.96\n" ] } ], "source": [ "#finding power factor\n", "\n", "#initialisation of variable\n", "from math import pi,tan,sqrt,sin,cos,acos,atan\n", "I=22.6;#current\n", "I2=28.00;\n", "V=120.0;#Voltage\n", "V2=280.0;\n", "\n", "#calculation\n", "Pt=3*I*V;\n", "Pl=I2*V2;\n", "Pf=Pl/Pt;\n", "\n", "#result\n", "print \"aparrent power is\",round(Pt/1000,2),\"kVA\"\n", "print \"dissipated power is\",round(Pl/1000,2),\"kW\"\n", "print \"power factor is\",round(Pl/Pt,2)\n", "\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Example 9.6,Page 474" ] }, { "cell_type": "code", "execution_count": 4, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "ratio is 0.72\n", "firing angle is 58 degrees\n", "dc voltage is 148.85 V\n", "time delay is 2.69 ms\n" ] } ], "source": [ "#finding firing angle, time delay,Vd\n", "\n", "#initialisation of variable\n", "from math import pi,tan,sqrt,sin,cos,acos,atan\n", "V=208.0;#voltage\n", "R=100.0;#load\n", "Vd=150.0;#V\n", "\n", "#calculation\n", "r=Vd/V;\n", "a=58;#degree\n", "Vd=3*2**.5*208*(cos(pi/3+a*pi/180)-cos(2*pi/3+a*pi/180))/pi;\n", "t=a*16.7/360;\n", "\n", "#result\n", "print \"ratio is\",round(r,2)\n", "print('firing angle is 58 degrees');\n", "print \"dc voltage is\",round(Vd,2), \"V\"\n", "print \"time delay is\",round(t,2), \"ms\"" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Example 9.7,Page 480" ] }, { "cell_type": "code", "execution_count": 5, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "max. current is 41.67 A\n", "dissipated power is 8.68 W\n" ] } ], "source": [ "#finding maximum current and power dissipated\n", "\n", "#initialisation of variable\n", "from math import pi,tan,sqrt,sin,cos,acos,atan\n", "P=150.0;#power\n", "V=8.0;#voltage\n", "R=.01;#resistance\n", "D=.5;#duty cycle\n", "\n", "#calculation\n", "I=P/.9/D/V;\n", "Ir=I*D**.5;\n", "Pq=Ir**2*R;\n", "\n", "#result\n", "print \"max. current is\",round(I,2), \"A\"\n", "print \"dissipated power is\",round(Pq,2),\"W\"" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Example 9.8,Page 489" ] }, { "cell_type": "code", "execution_count": 6, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "pwm fundamental frequency is 30.72 kHz\n", "output voltage is 9.46 V\n" ] } ], "source": [ "#finding fundamental frequency and output voltage\n", "\n", "#initialisation of variable\n", "from math import pi,tan,sqrt,sin,cos,acos,atan\n", "f1=60.0;#frequency\n", "V=150.0;#voltage\n", "f2=31.0;#kHz\n", "\n", "#calculation\n", "f3=f1*4;\n", "Vo=V*10**(-4.2);\n", "\n", "#result\n", "print \"pwm fundamental frequency is\",round(f3*2**7/1000,2), \"kHz\"\n", "print \"output voltage is\",round(Vo*1000,2), \"V\"" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Example 9.9,Page 491" ] }, { "cell_type": "code", "execution_count": 7, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "average voltage is 127.32 V\n", "\n", "Va-d @ 200Vin=4.2V\n", "\n", "\n", "pick R1=47kohm\n", "current through dividers is 2.62 mA\n", "R2 is 1.6 kohm\n", "capacitor is 27.01 microF\n" ] } ], "source": [ "#finding resistances,capacitor,average voltage\n", "\n", "#initialisation of variable\n", "from math import pi,tan,sqrt,sin,cos,acos,atan\n", "V=120.0;#load voltage\n", "f=60.0;#Hz\n", "Vp=200.0;#V\n", "Vd=5.0;#V\n", "\n", "\n", "#calculation\n", "Vdc=2*Vp/pi;\n", "Va=4.2;\n", "R1=47.0;\n", "I=(Vdc-Va)/R1;\n", "R2=Va/I;\n", "K=1.0/(1/R1+1/R2)# R1 \\\\ R2\n", "C=1.0/2/pi/3.8/K;\n", "\n", "#result\n", "print \"average voltage is\",round(Vdc,2), \"V\"\n", "print('\\nVa-d @ 200Vin=4.2V')\n", "print('\\n\\npick R1=47kohm')\n", "print \"current through dividers is\",round(I,2), \"mA\"\n", "print \"R2 is\",round(R2,2), \"kohm\"\n", "print \"capacitor is\",round(C*1000,2), \"microF\"" ] } ], "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": "2.7.6" } }, "nbformat": 4, "nbformat_minor": 0 }