From b9ebc3adfe1cd0b17f061dd639a5c76329e09afa Mon Sep 17 00:00:00 2001 From: nice Date: Tue, 16 Sep 2014 17:48:17 +0530 Subject: updating repo --- Principles_of_Power_System/chapter19.ipynb | 212 +++++++++++++++++++++++++++++ 1 file changed, 212 insertions(+) create mode 100755 Principles_of_Power_System/chapter19.ipynb (limited to 'Principles_of_Power_System/chapter19.ipynb') diff --git a/Principles_of_Power_System/chapter19.ipynb b/Principles_of_Power_System/chapter19.ipynb new file mode 100755 index 00000000..e6813a0f --- /dev/null +++ b/Principles_of_Power_System/chapter19.ipynb @@ -0,0 +1,212 @@ +{ + "metadata": { + "name": "", + "signature": "sha256:34f21e34d56021d11e412854716405b885521e02b7e263afa0b62d127f14da0d" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "heading", + "level": 1, + "metadata": {}, + "source": [ + "Chapter 19: Circuit Breakers" + ] + }, + { + "cell_type": "heading", + "level": 3, + "metadata": {}, + "source": [ + "Example 19.1, Page Number: 483" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "from __future__ import division\n", + "\n", + "#Variable declaration:\n", + "I = 1500 #rated current of circuit breaker(A)\n", + "MVA = 1000 #MVA rating of CB\n", + "V = 33 #voltage rating of circuit breaker(kV)\n", + "\n", + "\n", + "\n", + "#Calculation:\n", + "Is = MVA*10**6/(3**0.5*33*1000) #Rated symmetrical breaking current(A,rms)\n", + "Im = 2.55*Is #Rated making current(A,peak)\n", + "\n", + "\n", + "#Result:\n", + "print \"(i) Rated normal current is\",I,\"A\"\n", + "print \"(ii) Breaking capacity is\",MVA,\"MVA\"\n", + "print \"(iii) Rated symmetrical breaking current is\",round(Is),\"A (peak)\"\n", + "print \"(iv) Rated making current is\",round(Im),\"A (peak)\"\n", + "print \"(v) Short-time rating is\",round(Is),\"for 3 seconds\"\n", + "print \"(vi) Rated service voltage is\",V,\"kV (r.m.s)\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "(i) Rated normal current is 1500 A\n", + "(ii) Breaking capacity is 1000 MVA\n", + "(iii) Rated symmetrical breaking current is 17495.0 A (peak)\n", + "(iv) Rated making current is 44613.0 A (peak)\n", + "(v) Short-time rating is 17495.0 for 3 seconds\n", + "(vi) Rated service voltage is 33 kV (r.m.s)\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 3, + "metadata": {}, + "source": [ + "Example 19.2, Page Number: 484" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "from __future__ import division\n", + "import math\n", + "\n", + "#Variable declaration:\n", + "f = 50 #supply frequency(Hz)\n", + "V = 11 #voltage rating of generator(V)\n", + "C = 0.01 #distributed capacitance upto ckt breaker b/w phase and neutral(uF)\n", + "XL = 5 #reactance of neatral to earth(ohm)\n", + "\n", + "\n", + "#Calculation:\n", + "L = round(XL/(2*math.pi*f),4) #Inductance per phase(H)\n", + "Emax = round(2**0.5*V/3**0.5,2) #Maximum value of recovery voltage (phase to neutral)(V\n", + "E = 2*Emax #Peak re-striking voltage(kV)\n", + "fn = 1/(2*3.14*(L*C*10**-6)**0.5) #frequency of oscillations(Hz)\n", + "\n", + "#Since peak re-striking voltage occurs at a time t given by\n", + "t = 1/(2*fn) #s\n", + "r = E/t #kV/sec\n", + "\n", + "\n", + "\n", + "#Result:\n", + "print \"(i) Peak re-striking voltage is\",round(E,2),\"kV\"\n", + "print \"(ii) Frequency of oscillations is\",round(fn),\"Hz\"\n", + "print \"(iii)The average rate of rise of re-striking voltage\"\n", + "print \" upto the first peak is\",math.floor(r/1000),\"*10**3 kV/sec\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "(i) Peak re-striking voltage is 17.96 kV\n", + "(ii) Frequency of oscillations is 12628.0 Hz\n", + "(iii)The average rate of rise of re-striking voltage\n", + " upto the first peak is 453.0 *10**3 kV/sec\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 3, + "metadata": {}, + "source": [ + "Example 19.3, Page Number: 484" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "#Variable delaration:\n", + "t = 50*10**-6 #time to reach the peak re-striking voltage(s)\n", + "Vp = 100 #the peak re-striking voltage(kV)\n", + "\n", + "\n", + "#Calculation:\n", + "R = Vp/t #Average RRRV(kV/sec)\n", + "fn = 1/(2*t) #Natural frequency of oscillations(Hz)\n", + "\n", + "\n", + "#Result:\n", + "print \"Average RRRV is\",R/10**6,\"* 10**6 kV/sec\"\n", + "print \"Natural frequency of oscillations is\",fn,\"Hz\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Average RRRV is 2.0 * 10**6 kV/sec\n", + "Natural frequency of oscillations is 10000.0 Hz\n" + ] + } + ], + "prompt_number": 3 + }, + { + "cell_type": "heading", + "level": 3, + "metadata": {}, + "source": [ + "Example 19.4, Page Number: 485" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "from __future__ import division\n", + "\n", + "#Variable declaration:\n", + "Im = 11 #magnetising current of transformer(A)\n", + "Ic = 7 #chopped instantaneous value of current(A)\n", + "L = 35.2 #inductance (H)\n", + "C = 0.0023 #capacitance(uF)\n", + "\n", + "\n", + "#Result:\n", + "e = Ic*(L/(C*10**-6))**0.5 #Voltage across breaker contacts at chopping(V)\n", + "\n", + "\n", + "#Result:\n", + "print \"Voltage across breaker contacts at chopping is\",round(e/1000),\"kV\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Voltage across breaker contacts at chopping is 866.0 kV\n" + ] + } + ], + "prompt_number": 10 + } + ], + "metadata": {} + } + ] +} \ No newline at end of file -- cgit