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{
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"name": "",
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"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"CHAPTER 4 - Characteristics of AC motor"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"EXAMPLE 4.1 - PG NO:72"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Example 4.1, Page 72\n",
"import numpy\n",
"p1=numpy.poly1d([1, -3, 1])#Polynomial equation\n",
"print('Part a')\n",
"print('roots of the equation when slip at max torque')\n",
"x=numpy.roots(p1)\n",
"print(x)\n",
"\n",
"\n",
"p2=numpy.poly1d([1, -1.719,0.146])#polynomial equation in scilab function\n",
"y=numpy.roots(p2)\n",
"print('Part b')\n",
"print('roots of the equation when slip at max load')\n",
"print(y)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Part a\n",
"roots of the equation when slip at max torque\n",
"[ 2.61803399 0.38196601]\n",
"Part b\n",
"roots of the equation when slip at max load\n",
"[ 1.62939626 0.08960374]\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"EXAMPLE 4.3 - PG NO:76"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Example 4.3, Page 76\n",
"import numpy\n",
"p1=numpy.poly1d([0.04, -0.0266,.0016 ])#Polynomial equation\n",
"print('Part a')\n",
"print('roots of the equation that slip will run is')\n",
"x=numpy.roots(p1)\n",
"print(x)\n",
"#answers after calculation are accurate than textbook answers due to approximations"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Part a\n",
"roots of the equation that slip will run is\n",
"[ 0.59812426 0.06687574]\n"
]
}
],
"prompt_number": 5
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"EXAMPLE 4.5 - PG NO:81"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Example 4.5, page 81\n",
"import math\n",
"pole=24.\n",
"Ns=245.#in rpm\n",
"N=(120.*50.)/pole#synchronous speed in rpm\n",
"f=(N-Ns)/N\n",
"p=110.#in kw\n",
"T=(p*1000.*60.)/(2.*math.pi*Ns)\n",
"v1=440./math.sqrt(3)#in v\n",
"ws=(2*math.pi*250)/60\n",
"s=0.02\n",
"R=0.03125#in ohm\n",
"x=math.sqrt(((3*R*v1**2)/(T*ws*s))-(R/s)**2)#by rearranging formula\n",
"print'%s %.5f %s' %('Stator resistance per phase is=',x,'ohm')\n",
"#calculating original resistance\n",
"\n",
"#Example 4.1, Page 72\n",
"import numpy\n",
"p1=numpy.poly1d([3190,-3235,72.78 ])#Polynomial equation\n",
"print('Part a')\n",
"print('The value of original resistance is')\n",
"x=numpy.roots(p1)\n",
"print(x)\n",
"\n",
"#Taking r=0.99108\n",
"r=(0.99108-R)/1.25**2\n",
"\n",
"print'%s %.4f %s' %('The value of resistance to be added is =',r,' ohm')"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Stator resistance per phase is= 0.50358 ohm\n",
"Part a\n",
"The value of original resistance is\n",
"[ 0.99108634 0.02302024]\n",
"The value of resistance to be added is = 0.6143 ohm\n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"EXAMPLE 4.6 - PG NO:92"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Example 4.6, Page no 92\n",
"import math\n",
"print(\"Part ii\")\n",
"new_sin_delta=math.sin(math.pi/4)/.95\n",
"delta=math.asin(new_sin_delta)\n",
"x=math.degrees(delta)\n",
"print'%s %.2f %s' %('The value of delta is =',x,'degree')"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Part ii\n",
"The value of delta is = 48.10 degree\n"
]
}
],
"prompt_number": 4
}
],
"metadata": {}
}
]
}
|
