{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 13: Power Factor Improvement" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 13.1: EX13_1.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clear;\n", "clc;\n", "V_s=250;\n", "R_l=5;\n", "I_l=20;\n", "disp('for pf=1');\n", "V_l=sqrt(V_s^2-(R_l*I_l)^2); printf('load voltage=%.2f V',V_l);\n", "reg=(V_s-V_l)/V_s*100; printf('\nvoltage regulation=%.2f',reg);\n", "pf=1;\n", "P_l=V_l*I_l*pf; //load power\n", "P_r=V_s*I_l*pf; //max powwible system rating\n", "utf=P_l*100/P_r; printf('\nsystem utilisation factor=%.3f',utf);\n", "printf('\nenergy consumed(in units)=%.1f',P_l/1000);\n", "disp('for pf=.5');\n", "pf=.5;\n", "//(.5*V_l)^2+(.866*V_l+R_l*I_l)^2=V_s^2\n", "//after solving\n", "V_l=158.35; printf('load voltage=%.2f V',V_l);\n", "reg=(V_s-V_l)/V_s*100; printf('\nvoltage regulation=%.2f',reg);\n", "P_l=V_l*I_l*pf; //load power\n", "P_r=V_s*I_l; //max powwible system rating\n", "utf=P_l*100/P_r; printf('\nsystem utilisation factor=%.3f',utf);\n", "printf('\nenergy consumed(in units)=%.2f',P_l/1000);" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 13.2: to_calculate_the_capacitance_reqd.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clear;\n", "clc;\n", "f=50;\n", "V_s=230;\n", "disp('at no load');\n", "I_m=2;\n", "pf=.3;\n", "I_c=I_m*sind(acosd(pf));\n", "C=I_c/(2*%pi*f*V_s); printf('value of capacitance=%.3f uF',C*10^6);\n", "disp('at half full load');\n", "I_m=5;\n", "pf=.5;\n", "I_c=I_m*sind(acosd(pf));\n", "C=I_c/(2*%pi*f*V_s); printf('value of capacitance=%.3f uF',C*10^6);\n", "disp('at full load');\n", "I_m=10;\n", "pf=.7;\n", "I_c=I_m*sind(acosd(pf));\n", "C=I_c/(2*%pi*f*V_s); printf('value of capacitance=%.3f uF',C*10^6);" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 13.3: to_find_reqd_values_of_capacitor_and_inductor.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clear;\n", "clc;\n", "I_c=10;\n", "f=50;\n", "V_s=230;\n", "C=I_c/(2*%pi*f*V_s); printf('value of capacitance=%.3f uF',C*10^6);\n", "I_l=10;\n", "L=V_s/(2*%pi*f*I_l); printf('\nvalue of inductor=%.3f mH',L*1000);" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 13.4: to_find_the_firing_angle_of_the_TCR.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clc\n", "clear\n", "V_s=230;\n", "I_L=10;\n", "X_L=V_s/I_L;\n", "I_f1=6;\n", "//B=2*a-sin(2*a)\n", "B=2*%pi-I_f1*%pi*X_L/V_s;\n", "a=0;\n", "i=1;\n", "for a= 0:.01:360\n", " b=2*a*%pi/180-sind(2*a); \n", " if abs(B-b)<=.001; //by hit and trial\n", " i=2;\n", " break;\n", " end \n", "end\n", "printf('firing angle of TCR = %.1f deg',a);\n", "//(a-.01)*180/%pi);" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 13.5: to_calculate_the_effective_inductance_at_different_firing_angles.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clear;\n", "clc;\n", "L=.01;\n", "disp('for firing angle=90deg');\n", "a=90*%pi/180;\n", "L_eff=%pi*L/(2*%pi-2*a+sin(2*a)); printf('effective inductance=%.0f mH',L_eff*1000);\n", "disp('for firing angle=120deg');\n", "a=120*%pi/180;\n", "L_eff=%pi*L/(2*%pi-2*a+sin(2*a)); printf('effective inductance=%.3f mH',L_eff*1000);\n", "disp('for firing angle=150deg');\n", "a=150*%pi/180;\n", "L_eff=%pi*L/(2*%pi-2*a+sin(2*a)); printf('effective inductance=%.2f mH',L_eff*1000);\n", "disp('for firing angle=170deg');\n", "a=170*%pi/180;\n", "L_eff=%pi*L/(2*%pi-2*a+sin(2*a)); printf('effective inductance=%.3f H',L_eff);\n", "disp('for firing angle=175deg');\n", "a=175*%pi/180;\n", "L_eff=%pi*L/(2*%pi-2*a+sin(2*a)); printf('effective inductance=%.2f H',L_eff);\n", "disp('for firing angle=180deg');\n", "a=180*%pi/180;\n", "L_eff=%pi*L/(2*%pi-2*a+sin(2*a)); printf('effective inductance=%.3f H',L_eff);\n", "//random value at firing angle =180 is equivalent to infinity as in answer in book" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 13.6: to_find_value_of_inductance.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clear;\n", "clc;\n", "Q=100*10^3;\n", "V_s=11*10^3;\n", "f=50;\n", "L=V_s^2/(2*%pi*f*Q); printf('effective inductance=%.4f H',L);" ] } ], "metadata": { "kernelspec": { "display_name": "Scilab", "language": "scilab", "name": "scilab" }, "language_info": { "file_extension": ".sce", "help_links": [ { "text": "MetaKernel Magics", "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md" } ], "mimetype": "text/x-octave", "name": "scilab", "version": "0.7.1" } }, "nbformat": 4, "nbformat_minor": 0 }