From 2792e8d6ecab454e3cb8fb1ea1f26f1613bc1e1c Mon Sep 17 00:00:00 2001 From: nice Date: Mon, 15 Sep 2014 12:50:58 +0530 Subject: added books --- Fundamentals_of_Electrical_Machines/CH_7.ipynb | 400 +++++++++++++++++++++++++ 1 file changed, 400 insertions(+) create mode 100755 Fundamentals_of_Electrical_Machines/CH_7.ipynb (limited to 'Fundamentals_of_Electrical_Machines/CH_7.ipynb') diff --git a/Fundamentals_of_Electrical_Machines/CH_7.ipynb b/Fundamentals_of_Electrical_Machines/CH_7.ipynb new file mode 100755 index 00000000..167a7464 --- /dev/null +++ b/Fundamentals_of_Electrical_Machines/CH_7.ipynb @@ -0,0 +1,400 @@ +{ + "metadata": { + "name": "" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "heading", + "level": 1, + "metadata": {}, + "source": [ + "CHAPTER 7: THREE-PHASE INDUCTION MOTOR" + ] + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.1, Page number 246-247" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "#Variable declaration\n", + "V = 230.0 #Supply voltage(V)\n", + "P = 4.0 #Number of poles\n", + "f = 50.0 #Frequency(Hz)\n", + "N_l = 1445.0 #Full load speed(rpm)\n", + "\n", + "#Calculation\n", + "#For case(i)\n", + "N_s = 120*f/P #Synchronous speed(rpm)\n", + "#For case(ii)\n", + "s = (N_s-N_l)/N_s #Slip\n", + "#For case(iii)\n", + "f_r = s*f #Rotor frequency(Hz)\n", + "\n", + "#Result\n", + "print('(i) Synchronous speed , N_s = %.f rpm' %N_s)\n", + "print('(ii) Slip , s = %.4f ' %s)\n", + "print('(iii) Rotor frequency , f_r = %.1f Hz' %f_r)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "(i) Synchronous speed , N_s = 1500 rpm\n", + "(ii) Slip , s = 0.0367 \n", + "(iii) Rotor frequency , f_r = 1.8 Hz\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.2, Page number 247-248" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "#Variable declaration\n", + "E_BR = 120.0 #Voltage under blocked condition(V)\n", + "P = 4.0 #Number of poles\n", + "f = 50.0 #Frequency(Hz)\n", + "N_l = 1450.0 #Speed(rpm)\n", + "\n", + "#Calculation\n", + "N_s = 120*f/P #Synchronous speed(rpm)\n", + "s = (N_s-N_l)/N_s #Slip\n", + "f_r = s*f #Rotor frequency(Hz)\n", + "E_r = s*E_BR #Rotor voltage(V)\n", + "\n", + "#Result\n", + "print('Synchronous speed , N_s = %.f rpm' %N_s)\n", + "print('Rotor frequency , f_r = %.2f Hz' %f_r)\n", + "print('Rotor voltage , E_r = %.2f V' %E_r)\n", + "print('\\nNOTE : Changes in answer is due to precision i.e more number of decimal places')" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Synchronous speed , N_s = 1500 rpm\n", + "Rotor frequency , f_r = 1.67 Hz\n", + "Rotor voltage , E_r = 4.00 V\n", + "\n", + "NOTE : Changes in answer is due to precision i.e more number of decimal places\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.3, Page number 250" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "#Variable declaration\n", + "V_0 = 230.0 #Supply voltage(V)\n", + "P = 4.0 #Number of poles\n", + "T_0 = 230.0 #Original torque(N-m)\n", + "V_s = 150.0 #Stator voltage(V)\n", + "I_0 = 560.0 #Starting current(A)\n", + "\n", + "#Calculation\n", + "T_st = (V_s/V_0)**2*T_0 #Starting torque(N-m)\n", + "I_st = I_0*(V_s/V_0) #Starting current(A)\n", + "\n", + "#Result\n", + "print('Starting torque , T_st = %.1f N-m' %T_st)\n", + "print('Starting current , I_st = %.1f A' %I_st)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Starting torque , T_st = 97.8 N-m\n", + "Starting current , I_st = 365.2 A\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.4, Page number 254" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "#Variable declaration\n", + "f = 50.0 #Frequency(Hz)\n", + "P = 8.0 #Number of poles\n", + "a = 0.03 #Full load slip\n", + "R_2 = 0.01 #Rotor resistance per phase(ohm)\n", + "X_2 = 0.1 #Standstill reactance per phase(ohm)\n", + "\n", + "#Calculation\n", + "#For case(i)\n", + "N_s = 120*f/P #Synchronous speed(rpm)\n", + "s = R_2/X_2 #Slip at maximum torque\n", + "N_l = (1-s)*N_s #Rotor speed at maximum torque(rpm)\n", + "#For case(ii)\n", + "T = (s**2+a**2)/(2*a*s) #Ratio of maximum torque to full load torque\n", + "\n", + "#Result\n", + "print('(i) Speed at which maximum torque occurs , N_l = %.f rpm' %N_l)\n", + "print('(ii) Ratio of the maximum torque to full load torque , T_max/T_f = %.2f ' %T)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "(i) Speed at which maximum torque occurs , N_l = 675 rpm\n", + "(ii) Ratio of the maximum torque to full load torque , T_max/T_f = 1.82 \n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.5, Page number 260" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "#Variable declaration\n", + "V = 440.0 #Supply voltage(V)\n", + "P = 4.0 #Number of poles\n", + "P_ag = 1500.0 #Rotor input(W)\n", + "P_rcu = 250.0 #Copper loss(W)\n", + "f = 50.0 #Frequency(Hz)\n", + "\n", + "#Calculation\n", + "#For case(i)\n", + "s = P_rcu/P_ag #Slip\n", + "#For case(ii)\n", + "N_s = 120*f/P #Synchronous speed(rpm)\n", + "#For case(iii)\n", + "N_l = (1-s)*N_s #Shaft speed(rpm)\n", + "#For case(iv)\n", + "P_mech = (1-s)*P_ag #Mechanical power developed(W)\n", + "\n", + "#Result\n", + "print('(i) Slip , s = %.2f' %s)\n", + "print('(ii) Synchronous speed , N_s = %.f rpm' %N_s)\n", + "print('(iii) Shaft speed , N_l = %.f rpm' %N_l)\n", + "print('(iv) Mechanical power developed , P_mech = %.f W' %P_mech)\n", + "print('\\nNOTE : Changes in answer is due to precision i.e more number of decimal places')" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "(i) Slip , s = 0.17\n", + "(ii) Synchronous speed , N_s = 1500 rpm\n", + "(iii) Shaft speed , N_l = 1250 rpm\n", + "(iv) Mechanical power developed , P_mech = 1250 W\n", + "\n", + "NOTE : Changes in answer is due to precision i.e more number of decimal places\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.6, Page number 264" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "#Variable declaration\n", + "V_1 = 150.0 #Supply voltage(V)\n", + "P = 4.0 #Number of poles\n", + "f = 50.0 #Frequency(Hz)\n", + "Z_1 = complex(0.12,0.16) #Per phase standstill stator impedance(ohm)\n", + "Z_2 = complex(0.22,0.28) #Per phase standstill rotor impedance(ohm)\n", + "\n", + "#Calculation\n", + "Z_eq = Z_1+Z_2 #Equivalent impedance(ohm)\n", + "R_eq = Z_eq.real\n", + "P_mech = 3*V_1**2/(2*(R_eq+abs(Z_eq)))*10**-3 #Maximum mechanical power developed(kW)\n", + "R_2 = Z_2.real\n", + "s_mp = R_2/(abs(Z_eq)+R_2) #Slip\n", + "W_s = 2*math.pi*2*f/P #Synchronous speed(rad/s)\n", + "W = (1-s_mp)*W_s #Speed of rotor(rad/s)\n", + "T_mxm = P_mech*1000/W #Maximum torque(N-m) \n", + "\n", + "#Result\n", + "print('Maximum mechanical power , P_mech = %.2f kW' %P_mech)\n", + "print('Maximum torque , T_mxm = %.2f N-m' %T_mxm)\n", + "print('Slip , s_mp = %.2f ' %s_mp)\n", + "print('\\nNOTE : Changes in answer is due to precision i.e more number of decimal places')" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Maximum mechanical power , P_mech = 37.66 kW\n", + "Maximum torque , T_mxm = 334.65 N-m\n", + "Slip , s_mp = 0.28 \n", + "\n", + "NOTE : Changes in answer is due to precision i.e more number of decimal places\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.7, Page number 265-266" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "#Variable declaration\n", + "V = 440.0 #Supply voltage(V)\n", + "P = 6.0 #Number of poles\n", + "f = 50.0 #Frequency(Hz)\n", + "P_a = 45000.0 #Input power(W)\n", + "N_l = 900.0 #Speed(rpm)\n", + "P_tloss = 2000.0 #Total stator losses(W)\n", + "P_fw = 1000.0 #Friction and windage losses(W)\n", + "\n", + "#Calculation\n", + "N_s = 120*f/P #Synchronous speed(rpm)\n", + "s = (N_s-N_l)/N_s #Slip\n", + "P_ag = (P_a-P_tloss) #Air gap power(W)\n", + "P_rcu = s*P_ag #Rotor copper loss(W)\n", + "P_mech = P_ag-P_rcu #Mechanical power(W)\n", + "P_0 = P_mech-(P_tloss+P_fw) #Output power(W)\n", + "n = (P_0/P_ag)*100 #Efficiency(percent)\n", + "\n", + "#Result\n", + "print('(i) Slip , s = %.1f ' %s)\n", + "print('(ii) Rotor copper loss , P_rcu = %.f W' %P_rcu)\n", + "print('(iii) Shaft or Output power , P_0 = %.f W' %P_0)\n", + "print('(iv) Efficiency , \u03b7 = %.f percent' %n)\n", + "print('\\nNOTE : ERROR : Friction & windage losses are 1 kW not 1.5 kW as given in textbook question')" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "(i) Slip , s = 0.1 \n", + "(ii) Rotor copper loss , P_rcu = 4300 W\n", + "(iii) Shaft or Output power , P_0 = 35700 W\n", + "(iv) Efficiency , \u03b7 = 83 percent\n", + "\n", + "NOTE : ERROR : Friction & windage losses are 1 kW not 1.5 kW as given in textbook question\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 7.8, Page number 268-269" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "#Variable declaration\n", + "v_s = 120.0 #Train speed(km/h)\n", + "f = 50.0 #Stator frequency(Hz)\n", + "\n", + "#Calculation\n", + "v_s1 = v_s*1000/(60*60) #Train speed(m/s)\n", + "w = v_s1/(2*f) #Length of the pole-pitch(m)\n", + "\n", + "#Result\n", + "print('Length of the pole-pitch of linear induction motor , w = %.2f m' %w)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Length of the pole-pitch of linear induction motor , w = 0.33 m\n" + ] + } + ], + "prompt_number": 1 + } + ], + "metadata": {} + } + ] +} \ No newline at end of file -- cgit