From 5571c8f5bda1334edf8ef9d8c69928d46cc9f163 Mon Sep 17 00:00:00 2001 From: hardythe1 Date: Fri, 25 Jul 2014 13:33:31 +0530 Subject: removing unwanted and adding book --- .../chapter_21.ipynb | 1631 ++++++++++++++++++++ 1 file changed, 1631 insertions(+) create mode 100644 Electrical_Circuit_Theory_And_Technology/chapter_21.ipynb (limited to 'Electrical_Circuit_Theory_And_Technology/chapter_21.ipynb') diff --git a/Electrical_Circuit_Theory_And_Technology/chapter_21.ipynb b/Electrical_Circuit_Theory_And_Technology/chapter_21.ipynb new file mode 100644 index 00000000..373f5943 --- /dev/null +++ b/Electrical_Circuit_Theory_And_Technology/chapter_21.ipynb @@ -0,0 +1,1631 @@ +{ + "metadata": { + "name": "", + "signature": "sha256:18b2ae9034d59ad1d2a71a370085420c43adb19c1da344e7757efdb47969ddb0" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Chapter 21: D.c. machines

" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 1, page no. 354

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "Z = 600;# no. of conductors\n", + "c = 2;# for a wave winding\n", + "p = 4;# no. of pairs\n", + "n = 625/60;# in rev/sec\n", + "Phi = 20E-3;# in Wb\n", + "\n", + "#calculation:\n", + " #Generated e.m.f., E = 2*p*Phi*n*Z/c\n", + "E = 2*p*Phi*n*Z/c\n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n the generated e.m.f is \",round(E,2),\" V \"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " the generated e.m.f is 500.0 V " + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 2, page no. 354

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "Z = 50*16;# no. of conductors\n", + "p = 1;# let no. of pairs\n", + "c = 2*p;# for a lap winding\n", + "Phi = 30E-3;# in Wb\n", + "E = 240;# in Volts\n", + "\n", + "#calculation:\n", + " #Generated e.m.f., E = 2*p*Phi*n*Z/c\n", + " #Rearranging gives, speed\n", + "n = E*c/(2*p*Phi*Z)\n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n the speed at which the machine must be driven is \",round(n,2),\" rev/sec \"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " the speed at which the machine must be driven is 10.0 rev/sec " + ] + } + ], + "prompt_number": 2 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 3, page no. 354

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "Z = 1200;# no. of conductors\n", + "p = 1;# let, no. of pairs\n", + "c = 2*p;# for a lap winding\n", + "Phi = 30E-3;# in Wb\n", + "n = 500/60;# in rev/sec\n", + "\n", + "#calculation:\n", + " #Generated e.m.f., E = 2*p*Phi*n*Z/c\n", + "E = 2*p*Phi*n*Z/c\n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n Generated e.m.f. is \",round(E,2),\" V \"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " Generated e.m.f. is 300.0 V " + ] + } + ], + "prompt_number": 3 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 4, page no. 355

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "Z = 1200;# no. of conductors\n", + "p = 4;# let, no. of pairs\n", + "c = 2;# for a wave winding\n", + "Phi = 30E-3;# in Wb\n", + "n = 500/60;# in rev/sec\n", + "\n", + "#calculation:\n", + " #Generated e.m.f., E = 2*p*Phi*n*Z/c\n", + "E = 2*p*Phi*n*Z/c\n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n Generated e.m.f. is \",round(E,2),\" V \"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " Generated e.m.f. is 1200.0 V " + ] + } + ], + "prompt_number": 4 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 5, page no. 355

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "E1 = 150; # in Volts\n", + "x = 0.2;\n", + "\n", + "#calculation:\n", + "E2 = E1*(1- x)\n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n Generated e.m.f. is \",round(E2,2),\" V \"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " Generated e.m.f. is 120.0 V " + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 6, page no. 356

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "n1 = 30;# in rev/sec\n", + "E1 = 200;# in Volts\n", + "n2 = 20;# in rev/sec\n", + "E2 = 250;# in Volts\n", + "\n", + "#calculation:\n", + " #generated e.m.f., E proportional to phi*w and since w = 2*pi*n, then\n", + " # E proportional to phi*n\n", + " # E1/E2 = Phi1*n1/(Phi2*n2)\n", + " # let Phi2/Phi1 = Phi\n", + "Phi = E2*n1/(E1*n2)\n", + "Phi_inc = (Phi - 1)*100#/in percent\n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n percentage increase in the flux per pole is \",round(Phi_inc,2),\" percent \"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " percentage increase in the flux per pole is 87.5 percent " + ] + } + ], + "prompt_number": 5 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 7, page no. 357

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "Ra = 0.30;# in ohms\n", + "Ia = 30;# in Amperes\n", + "E = 200;# in Volts\n", + "\n", + "#calculation:\n", + " #terminal voltage,\n", + " #V = E - Ia*Ra\n", + "V = E - Ia*Ra\n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n terminal voltage of a generator is \",round(V,2),\" V \"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " terminal voltage of a generator is 191.0 V " + ] + } + ], + "prompt_number": 6 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 8, page no. 357

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "RL = 60;# in ohms\n", + "Ia = 8;# in Amperes\n", + "Ra = 1;# in ohms\n", + "\n", + "#calculation:\n", + " #terminal voltage,\n", + " #V = Ia*RL\n", + "V = Ia*RL\n", + " #Generated e.m.f., E\n", + "E = V + Ia*Ra\n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n (a)terminal voltage is \",round(V,2),\" V \"\n", + "print \"\\n (b)generated e.m.f. is \",round(E,2),\" V \"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " (a)terminal voltage is 480.0 V \n", + "\n", + " (b)generated e.m.f. is 488.0 V " + ] + } + ], + "prompt_number": 7 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 9, page no. 357

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "E1 = 150;# in Volts\n", + "n1 = 20;# in rev/sec\n", + "Phi1 = 0.10;# in Wb\n", + "n2 = 25;# in rev/sec\n", + "Phi2 = 0.10;# in Wb\n", + "n3 = 20;# in rev/sec\n", + "Phi3 = 0.08;# in Wb\n", + "n4 = 24;# in rev/sec\n", + "Phi4 = 0.07;# in Wb\n", + "\n", + "#calculation:\n", + " #generated e.m.f., E proportional to phi*w and since w = 2*pi*n, then\n", + " # E proportional to phi*n\n", + " # E1/E2 = Phi1*n1/(Phi2*n2)\n", + "E2 = E1*Phi2*n2/(Phi1*n1)\n", + "E3 = E1*Phi3*n3/(Phi1*n1)\n", + "E4 = E1*Phi4*n4/(Phi1*n1)\n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n (a)the generated e.m.f is \",round(E2,2),\" V \"\n", + "print \"\\n (b)generated e.m.f. is \",round(E3,2),\" V \"\n", + "print \"\\n (c)generated e.m.f. is \",round(E4,2),\" V \"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " (a)the generated e.m.f is 187.5 V \n", + "\n", + " (b)generated e.m.f. is 120.0 V \n", + "\n", + " (c)generated e.m.f. is 126.0 V " + ] + } + ], + "prompt_number": 8 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 10, page no. 359

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "Ps = 20000;# in Watts\n", + "Vs = 200;# in Volts\n", + "Rs = 0.1;# in ohms\n", + "Rf = 50;# in ohms\n", + "Ra = 0.04;# in ohms\n", + "\n", + "#calculation:\n", + " #Load current, I\n", + "Is = Ps/Vs\n", + " #Volt drop in the cables to the load\n", + "Vd = Is*Rs\n", + " #Hence terminal voltage,\n", + "V = Vs + Vd\n", + " #Field current, If\n", + "If = V/Rf\n", + " #Armature current\n", + "Ia = If + Is\n", + " #Generated e.m.f. E\n", + "E = V + Ia*Ra\n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n (a)terminal voltage is \",round(V,2),\" V \"\n", + "print \"\\n (b)generated e.m.f. is \",round(E,2),\" V \"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " (a)terminal voltage is 210.0 V \n", + "\n", + " (b)generated e.m.f. is 214.17 V " + ] + } + ], + "prompt_number": 9 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 11, page no. 361

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "Is = 80;# in amperes\n", + "Vs = 200;# in Volts\n", + "Rf = 40;# in ohms\n", + "Rse = 0.02;# in ohms\n", + "Ra = 0.04;# in ohms\n", + "\n", + "#calculation:\n", + " #Volt drop in series winding\n", + "Vse = Is*Rse\n", + " #P.d. across the field winding = p.d. across armature\n", + "V1 = Vs + Vse\n", + " #Field current, If\n", + "If = V1/Rf\n", + " #Armature current\n", + "Ia = If + Is\n", + " #Generated e.m.f. E\n", + "E = V1 + Ia*Ra\n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n generated e.m.f. is \",round(E,2),\" V \"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " generated e.m.f. is 205.0 V " + ] + } + ], + "prompt_number": 12 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 12, page no. 363

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "Ps = 10000;# in Watt\n", + "Pl = 600;# in Watt\n", + "Ra = 0.75;# in ohms\n", + "Rf = 125;# in ohms\n", + "V = 250;# in Volts\n", + "\n", + "#calculation:\n", + " #Output power Ps = V*I\n", + " #from which, load current I\n", + "I = Ps/V\n", + " #Field current, If\n", + "If = V/Rf\n", + " #Armature current\n", + "Ia = If + I\n", + " #Efficiency,\n", + "eff = Ps*100/((V*I) + (Ia*Ia*Ra) + (If*V) + (Pl))# in Percent\n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n Efficiency is \",round(eff,2),\" percent \"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " Efficiency is 80.5 percent " + ] + } + ], + "prompt_number": 13 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 13, page no. 364

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "Ra = 0.2;# in ohms\n", + "V = 240;# in Volts\n", + "Ia = 50;# in Amperes\n", + "\n", + "#calculation:\n", + " #For a motor, V = E + Ia*Ra\n", + "E = V - Ia*Ra\n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n back e.m.f. is \",round(E,2),\" V \"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " back e.m.f. is 230.0 V " + ] + } + ], + "prompt_number": 14 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 14, page no. 365

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "Ra = 0.25;# in ohms\n", + "V = 300;# in Volts\n", + "Ig = 100;# in Amperes\n", + "Im = 80;# in Amperes\n", + "\n", + "#calculation:\n", + " #As a generator, generated e.m.f.,\n", + " # E = V + Ia*Ra\n", + "Eg = V + Ig*Ra\n", + " #For a motor, generated e.m.f. (or back e.m.f.),\n", + " # E = V - Ia*Ra\n", + "E = V - Im*Ra\n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n (a)As a generator, generated e.m.f. is \",round(Eg,2),\" V \"\n", + "print \"\\n (b)back e.m.f. is \",round(E,2),\" V \"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " (a)As a generator, generated e.m.f. is 325.0 V \n", + "\n", + " (b)back e.m.f. is 280.0 V " + ] + } + ], + "prompt_number": 15 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 15, page no. 366

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "p = 4;\n", + "c = 2;# for a wave winding\n", + "Phi = 25E-3;# Wb\n", + "Z = 900;\n", + "Ia = 30;# in Amperes\n", + "\n", + "#calculation:\n", + " #torque T = p*Phi*Z*Ia/(pi*c)\n", + "T = p*Phi*Z*Ia/(1*math.pi*c)\n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n the torque exerted is \",round(T,2),\" Nm \"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " the torque exerted is 429.72 Nm " + ] + } + ], + "prompt_number": 16 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 16, page no. 366

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "V = 350;# in Volts\n", + "Ra = 0.5;# in ohms\n", + "n = 15;# in rev/sec\n", + "Ia = 60;# in Amperes\n", + "\n", + "#calculation:\n", + " #Back e.m.f. E = V - Ia*Ra\n", + "E = V - Ia*Ra\n", + " #torque T = E*Ia/(2*n*pi)\n", + "T = E*Ia/(2*n*math.pi)\n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n the torque exerted is \",round(T,2),\" Nm \"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " the torque exerted is 203.72 Nm " + ] + } + ], + "prompt_number": 17 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 17, page no. 366

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "p = 1;# let\n", + "c = 2*p;# for a lap winding\n", + "Phi = 20E-3;# Wb\n", + "Z = 500;\n", + "V = 250;# in Volts\n", + "Ra = 1;# in ohms\n", + "Ia = 40;# in Amperes\n", + "\n", + "#calculation:\n", + " #Back e.m.f. E = V - Ia*Ra\n", + "E = V - Ia*Ra\n", + " #E.m.f. E = 2*p*Phi*n*Z/c\n", + " # rearrange,\n", + "n = E*c/(2*p*Phi*Z)\n", + " #torque T = E*Ia/(2*n*pi)\n", + "T = E*Ia/(2*n*math.pi)\n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n (a)speed n is \",round(n,2),\" rev/sec \"\n", + "print \"\\n (b)the torque exerted is \",round(T,2),\" Nm \"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " (a)speed n is 21.0 rev/sec \n", + "\n", + " (b)the torque exerted is 63.66 Nm " + ] + } + ], + "prompt_number": 18 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 18, page no. 367

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "T1 = 25;# in Nm\n", + "T2 = 35;# in Nm\n", + "Ia1 = 16;# in Amperes\n", + "V = 100;# in Volts\n", + "x = 0.15;\n", + "\n", + " #calculation:\n", + " #the shaft torque T of a generator is proportional to (phi*Ia),\n", + " #where Phi is the flux and Ia is the armature current. Thus, T = k*Phi*Ia, where k is a constant.\n", + " #The torque at flux phi1 and armature current Ia1 is T1 = k*Phi1*Ia1.\n", + " #similarly T2 = k*Phi2*Ia2\n", + "\n", + "Ia2 = T2*Ia1/(0.85*T1)\n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n armature current at the new value of torque is \",round(Ia2,2),\" A \"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " armature current at the new value of torque is 26.35 A " + ] + } + ], + "prompt_number": 19 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 19, page no. 367

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "T = 12;# in Nm\n", + "I = 15;# in Amperes\n", + "V = 100;# in Volts\n", + "n = 1500/60;# in rev/sec\n", + "\n", + "#calculation:\n", + " #the efficiency of a generator = (output power/input power)*100 %\n", + " #The output power is the electrical output, i.e. VI watts. \n", + " #The input power to a generator is the mechanical power in the shaft driving the generator, \n", + " #i.e. T*w or T(2*pi*n) watts, where T is the torque in Nm and n is speed of rotation in rev/s. Hence, for a generator \n", + " #efficiency = V*I*100/(T*2*pi*n) %\n", + "eff = V*I*100/(T*2*math.pi*n)# in Percent\n", + " #The input power = output power + losses\n", + " # hence, T*2*math.pi*n = V*I + losses\n", + "Pl = T*2*math.pi*n - V*I\n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n (a) efficiency is \",round(eff,2),\" % \"\n", + "print \"\\n (b) power loss is \",round(Pl,2),\" W \"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " (a) efficiency is 79.58 % \n", + "\n", + " (b) power loss is 384.96 W " + ] + } + ], + "prompt_number": 20 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 20, page no. 368

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "Rf = 150;# in Ohms\n", + "Ra = 0.4;# in Ohms\n", + "I = 30;# in Amperes\n", + "V = 240;# in Volts\n", + "\n", + "#calculation:\n", + " #Field current If\n", + "If = V/Rf\n", + " #Supply current I = Ia + If\n", + " #Hence armature current, Ia\n", + "Ia = I - If\n", + " #Back e.m.f. E = V -\u0004 Ia*Ra\n", + "E = V - (Ia*Ra)\n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n (a) current in the armature is \",round(Ia,2),\" A \"\n", + "print \"\\n (b) Back e.m.f. E is \",round(E,2),\" V \"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " (a) current in the armature is 28.4 A \n", + "\n", + " (b) Back e.m.f. E is 228.64 V " + ] + } + ], + "prompt_number": 21 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 21, page no. 370

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "Ia1 = 30;# in Amperes\n", + "Ia2 = 45;# in Amperes\n", + "Ra = 0.4;# in ohm\n", + "n1 = 1350/60;# in Rev/sec\n", + "V = 200;# in Volts\n", + "\n", + "#calculation:\n", + " #The relationship E proportional to (Phi*n) applies to both generators and motors. For a motor,\n", + " #E = V - (Ia*Ra)\n", + "E1 = V - (Ia1*Ra)\n", + "E2 = V - (Ia2*Ra)\n", + " #The relationship, E1/E2 = Phi1*n1/Phi2*n2, applies to both generators and motors.\n", + " #Since the flux is constant, Phi1 = Phi2\n", + "n2 = E2*n1/(E1)\n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n the speed of the motor is \",round(n2,2),\" rev/sec \"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " the speed of the motor is 21.78 rev/sec " + ] + } + ], + "prompt_number": 22 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 22, page no. 370

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "Ia1 = 30;# in Amperes\n", + "Ra = 0.4;# in ohm\n", + "n = 800/60;# in Rev/sec\n", + "V = 220;# in Volts\n", + "x= 0.1;\n", + "\n", + "#calculation:\n", + " #For a d.c. shunt-wound motor, E = V - (Ia*Ra),Hence initial generated e.m.f.,\n", + "E1 = V - (Ia1*Ra)\n", + " #The generated e.m.f. is also such that E proportional to (Phi*n) \n", + " #so at the instant the flux is reduced, the speed has not had time to change, and\n", + "E = E1*(1-x)\n", + " #Hence, the voltage drop due to the armature resistance is\n", + "Vd = V - E\n", + " #The instantaneous value of the current is\n", + "Ia = Vd/Ra\n", + " #T proportional to (Phi*Ia), since the torque is constant,\n", + " #Phi1*Ia1 = Phi2*Ia2, The flux 8 is reduced by 10%, hence\n", + "Ia2 = Ia1/0.9\n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n (a)instantaneous value of the current \",round(Ia,2),\" A \"\n", + "print \"\\n (b)steady state value of armature current, \",round(Ia2,2),\" A \"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " (a)instantaneous value of the current 82.0 A \n", + "\n", + " (b)steady state value of armature current, 33.33 A " + ] + } + ], + "prompt_number": 23 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 23, page no. 372

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "Ia1 = 15;# in Amperes\n", + "Ia2 = 30;# in Amperes\n", + "Rf = 0.3;# in ohms\n", + "Ra = 0.2;# in ohm\n", + "n1 = 24;# in Rev/sec\n", + "V = 240;# in Volts\n", + "x= 2;\n", + "\n", + "#calculation:\n", + " #generated e.m.f., E, at initial load, is given by\n", + "E1 = V - Ia1*(Ra + Rf)\n", + " #When the current is increased to 30 A, the generated e.m.f. is given by:\n", + "E2 = V - Ia2*(Ra + Rf)\n", + " #E proportional to (Phi*n)\n", + " #E1/E2 = Phi1*n1/Phi2*n2\n", + "n2 = E2*n1/(2*E1) \n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n (a)generated e.m.f., E is \",round(E1,2),\" V \"\n", + "print \"\\n (b)speed of motor, n2, \",round(n2,2),\" rev/sec \"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " (a)generated e.m.f., E is 232.5 V \n", + "\n", + " (b)speed of motor, n2, 11.61 rev/sec " + ] + } + ], + "prompt_number": 3 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 24, page no. 374

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "I = 80;# in Amperes\n", + "C = 1500;# in Watt\n", + "Rf = 40;# in ohms\n", + "Ra = 0.2;# in ohm\n", + "n = 1000/60;# in Rev/sec\n", + "V = 320;# in Volts\n", + "\n", + "#calculation:\n", + " #Field current, If\n", + "If = V/Rf\n", + " #Armature current Ia\n", + "Ia = I - If\n", + " #Efficiency\n", + "eff = ((V*I - (Ia*Ia*Ra) - (If*V) - C)/(V*I))*100 # in percent\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n efficiency is\",round(eff,2),\"%\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " efficiency is 80.09 %" + ] + } + ], + "prompt_number": 25 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 25, page no. 374

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "I = 40;# in Amperes\n", + "Rf = 0.05;# in ohms\n", + "Ra = 0.15;# in ohm\n", + "V = 250;# in Volts\n", + "\n", + "#calculation:\n", + " #However for a series motor, If = 0 and the Ia*Ia*Ra loss needs to be I*I*(\u0011Ra + Rf)\n", + " #For maximum efficiency I*I*\u0011(Ra + Rf) = C\n", + " #Efficiency\n", + "eff = ((V*I - (2*I*I*(Ra + Rf)))/(V*I))*100 # in percent\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n efficiency is\",round(eff,2)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " efficiency is 93.6" + ] + } + ], + "prompt_number": 25 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 26, page no. 375

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "T = 15;# in Nm\n", + "n = 1200/60;# in rev/sec\n", + "eff = 0.8;\n", + "V = 200;# in Volts\n", + "\n", + "#calculation:\n", + "I = T*2*math.pi*n/(V*eff)\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n current supplied, I is \",round(I,2),\"A\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " current supplied, I is 11.78 A" + ] + } + ], + "prompt_number": 26 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 27, page no. 376

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "R = 2;# in ohm\n", + "n = 30;# in rev/sec\n", + "I = 10;# in A\n", + "C = 300;# in Watt\n", + "V = 400;# in Volts\n", + "\n", + "#calculation:\n", + " #Efficiency\n", + "eff = ((V*I - (I*I*R) - C)/(V*I))*100 # in percent\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n efficiency is\",round(eff,2),\"%\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " efficiency is 87.5 %" + ] + } + ], + "prompt_number": 27 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 28, page no. 378

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "Ia1 = 120;# in A\n", + "Ia2 = 60;# in A\n", + "Ra = 0.2;# in ohm\n", + "n1 = 10;# in rev/sec\n", + "R = 0.5;# in ohm\n", + "x = 0.8;\n", + "V = 500;# in Volts\n", + "\n", + "#calculation:\n", + " #back e.m.f. at Ia1\n", + "E1 = V - Ia1*Ra\n", + " #at Ia2\n", + "E2 = V - Ia2*(Ra + R)\n", + " #E1/E2 = Phi1*n1/Phi2*n2\n", + "n2 = n1*E2/E1\n", + " #Back e.m.f. when Ia2\n", + "E3 = V - Ia2*Ra\n", + "n3 = n1*E3/(x*E1)\n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n (a)speed n2 is \",round(n2,2),\" rev/sec\"\n", + "print \"\\n (b)speed n3 is \",round(n3,2),\" rev/sec\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " (a)speed n2 is 9.62 rev/sec\n", + "\n", + " (b)speed n3 is 12.82 rev/sec" + ] + } + ], + "prompt_number": 2 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 29, page no. 379

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "Ia1 = 90;# in Amperes\n", + "Ra = 0.1;# in ohm\n", + "Rse = 0.05;# in ohm\n", + "Rd = 0.2;# in Ohm\n", + "n1 = 15;# in rev/sec\n", + "V = 300;# in Volts\n", + "\n", + "#calculation:\n", + " #e.m.f. E1\n", + "E1 = V - Ia1*(Ra + Rse)\n", + " #With the Rd diverter in parallel with Rse\n", + " #equivalent resistance, Re\n", + "Re = Rd*Rse/(Rd+Rse)\n", + " #Torque, T proprtional to Ia*Phi and for full load torque, Ia1*Phi1 = Ia2*Phi2\n", + " #Since flux is proportional to field current Phi1 proportional to Ta1 and Phi2 Proportional to I1\n", + "I1 = (Ia1*Ia1*0.8)**0.5\n", + " #By current division, current I1\n", + "Ia2 = I1/(Rd/(Rd + Rse))\n", + " #Hence e.m.f. E2\n", + "E2 = V - Ia2*(Ra + Re)\n", + " #E1/E2 = Phi1*n1/Phi2*n2\n", + "n2 = E2*Ia1*n1/(I1*E1)\n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n speed n2 is \",round(n2,2),\" rev/sec\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " speed n2 is 16.74 rev/sec" + ] + } + ], + "prompt_number": 29 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "

Example 30, page no. 380

" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "\n", + "from __future__ import division\n", + "import math\n", + "#initializing the variables:\n", + "Ia1 = 25;# in Amperes\n", + "Ra = 0.4;# in ohm\n", + "Rse = 0.2;# in ohm\n", + "n1 = 800/60;# in rev/sec\n", + "n2 = 600/60;# in rev/sec\n", + "V = 400;# in Volts\n", + "\n", + "#calculation:\n", + " #e.m.f. E1\n", + "E1 = V - Ia1*(Ra + Rse)\n", + " #At n2, since the current is unchanged, the flux is unchanged.\n", + " #E1/E2 = n1/n2\n", + "E2 = E1*n2/n1\n", + " #and E2 = V - Ia1(\u0011Ra + Rse + R)\n", + "R = (V - E2)/Ia1 - Ra - Rse\n", + "\n", + "\n", + "#Results\n", + "print \"\\n\\n Result \\n\\n\"\n", + "print \"\\n Resistance is \",round(R,2),\" ohm\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + "\n", + " Result \n", + "\n", + "\n", + "\n", + " Resistance is 3.85 ohm" + ] + } + ], + "prompt_number": 30 + } + ], + "metadata": {} + } + ] +} \ No newline at end of file -- cgit