From d36fc3b8f88cc3108ffff6151e376b619b9abb01 Mon Sep 17 00:00:00 2001 From: kinitrupti Date: Fri, 12 May 2017 18:40:35 +0530 Subject: Revised list of TBCs --- .../Chapter4_1.ipynb | 348 +++++++++++++++++++++ 1 file changed, 348 insertions(+) create mode 100755 backup/Fundamentals_of_Electrical_Drives_version_backup/Chapter4_1.ipynb (limited to 'backup/Fundamentals_of_Electrical_Drives_version_backup/Chapter4_1.ipynb') diff --git a/backup/Fundamentals_of_Electrical_Drives_version_backup/Chapter4_1.ipynb b/backup/Fundamentals_of_Electrical_Drives_version_backup/Chapter4_1.ipynb new file mode 100755 index 00000000..ca34966f --- /dev/null +++ b/backup/Fundamentals_of_Electrical_Drives_version_backup/Chapter4_1.ipynb @@ -0,0 +1,348 @@ +{ + "metadata": { + "name": "" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "heading", + "level": 1, + "metadata": {}, + "source": [ + "Chapter 4: Selection of Motor Power Rating" + ] + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example No:4.1, Page No:47" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "from __future__ import division\n", + "\n", + "#variable declaration\n", + "T_min=40 # minimum temperature rise in degree Celsius\n", + "T_r=15 # temperature rise when the load is declutched continously in degree Celsius\n", + "t_c=10 # time for which the motor is clutched to its load in sec\n", + "t_d=20 # time for which the motor is declutched to run on no-load in sec\n", + "C= 60 # time constants for both heating and cooling \n", + "\n", + "#calculation\n", + "x=math.exp(-t_d/C)\n", + "y=math.exp(-t_c/C)\n", + "\n", + "theta2= (T_min-T_r*(1-x))/x #since T_min=T_r(1-x)+theta2*x\n", + "theta_ss=(theta2-T_min*y)/(1-y) #since theta2=theta_ss(1-y)+T_min*y\n", + "\n", + "#results\n", + "print\"\\n maximum temperature during the duty cycle :\",round(theta2,1),\"\u00b0C\"\n", + "print\"\\n temperature when the load is clutched continously :\",round(theta_ss,1),\"\u00b0C\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + " maximum temperature during the duty cycle : 49.9 \u00b0C\n", + "\n", + " temperature when the load is clutched continously : 104.4 \u00b0C\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example No:4.2, Page No:52" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "from __future__ import division\n", + "\n", + "#variable declaration\n", + "N=200 #full speed of the motor in rpm\n", + "Tc=25000 #constant torque in N-m\n", + "J=10000 #moment of inertia referred to te motor shaft in Kg-m2\n", + "\n", + "#duty cycles\n", + "t1=10 #rolling at full speed and at constant torque\n", + "t2=1 #no load operation at full speed\n", + "t3=5 #speed reversal from N to -N\n", + "t4=1 #no load operation at full speed\n", + "\n", + "T5=20000 #torque in N-m\n", + "t5=15 #rolling at full speed and at a torque T1\n", + "\n", + "t6=1 #no operation at full speed\n", + "t7=5 #speed reversal from -N to N\n", + "t8=1 #no load operation\n", + "\n", + "#calculation\n", + "Tr=J*(N-(-N))*2*math.pi/60/5 #torque during reversal\n", + "x=Tc**2*t1+Tr**2*t3+T5**2*t5+Tr**2*t7\n", + "t=t1+t2+t3+t4+t5+t6+t7+t8 #total time\n", + "Trms=math.sqrt(x/t) #rms torque\n", + "\n", + "Trated=Trms #rated torque is equal to the rms torque\n", + "Pr=Trated*2*math.pi*200/60 #power rating\n", + "ratio=Tr/Trms #ratio of reversal torque to the rms torque\n", + "\n", + "#results\n", + "#answer in the book is wrong\n", + "print\"\\n motor torque is :Trms=\",round(Trms),\"N-m\"\n", + "if ratio<2:\n", + " print\" motor can be rated as equal to Trms\"\n", + "print\" Power rating : P=\",round(Pr*1e-3,3),\"kW\" " + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "\n", + " motor torque is :Trms= 45975.0 N-m\n", + " motor can be rated as equal to Trms\n", + " Power rating : P= 962.895 kW\n" + ] + } + ], + "prompt_number": 3 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example No:4.3, Page No:53" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "import scipy\n", + "from scipy import integrate\n", + "\n", + "#variable declaration\n", + "P1=400 #load in kW\n", + "P2=500 #load in KW\n", + "Pmax=P2\n", + "#duty cycles in minutes\n", + "t1=5 #load rising from 0 to P1 \n", + "t2=5 #uniform load of P2 \n", + "t3=4 #regenerative power equal to P1\n", + "t4=2 #motor remains idle\n", + "\n", + "#calculation\n", + "a = lambda x: (P1/5*x)**2\n", + "t=integrate.quad(a,0,t1)\n", + "P11=math.sqrt(t[0]/t1)\n", + "x=P11**2*t1+P2**2*t2+P1**2*t3\n", + "t=t1+t2+t3+t4 #total time\n", + "Prms=math.sqrt(x/t)\n", + "\n", + "#results\n", + "y=2*Prms\n", + "if P2