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{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 21: Protective Relays"
]
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 21.1, Page Number: 507"
]
},
{
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"input": [
"from __future__ import division\n",
"\n",
"#Variable declaration:\n",
"Is = 5 #rated secondary current of C.T\n",
"CS = 1.25 #current setting\n",
"TSM = 0.6 #time setting multiplier\n",
"IF = 4000 #fault current(A)\n",
"CR = 400/5 #current ratio of CT\n",
"\n",
"#Calculation:\n",
"Ipc = Is*CS #pick-up current(A)\n",
"If = IF*CR #Fault current in relay coil(A)\n",
"PSM = If/Ipc #plug setting multiplier\n",
"#Corresponding to the plug-setting multiplier of 8 given in fig.21.16,\n",
"#the time of operation is 3.5 seconds.\n",
"top = 3.5*TSM #Actual relay operating time(s)\n",
"\n",
"\n",
"#Result:\n",
"print \"The relay operating time is\",top,\"seconds\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The relay operating time is 2.1 seconds\n"
]
}
],
"prompt_number": 2
}
],
"metadata": {}
}
]
}
|
