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{
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"name": "",
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"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"CHAPTER19 : COMPUTATIONS OF SYNCHRONOUS MOTOR PERFORMANCE"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example E01 : Pg 755"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"# a\n",
"import math\n",
"efficiency = 0.9; \n",
"Pi = 200.*746./efficiency; # input power \n",
"x = 11.; # reactance of the motor\n",
"V1 = 2300./math.sqrt(3.); # voltage rating \n",
"delta = 15.*math.pi/180.; # power angle\n",
"Ef = Pi*x/(3.*V1*math.sin(delta)); # the induced excitation voltage per phase \n",
"print '%s' %(\"a\")\n",
"print '%s %.2f' %(\"the induced excitation voltage per phase = \",Ef)\n",
"\n",
"# b\n",
"z = complex(0,x); # impedance of the motor \n",
"ef = complex(Ef*math.cos(-delta),Ef*math.sin(-delta));\n",
"\n",
"Ia = (V1 - ef)/z ; # armature current \n",
"print '%s' %(\"b\")\n",
"print \"armatur current = \",Ia\n",
"\n",
"# c\n",
"theata =0.693;# math.atan(imag(Ia)/real(Ia)); # phase difference between Ia and V1\n",
"pf = math.cos(theata); # power factor \n",
"\n",
"print '%s' %(\"c\")\n",
"print '%s %.2f' %(\"power factor = \",pf)\n",
"\n",
"if math.sin(theata)> 0 :\n",
" print '%s' %(\"leading\")\n",
"else :\n",
" print '%s' %(\"lagging\")\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"a\n",
"the induced excitation voltage per phase = 1768.62\n",
"b\n",
"armatur current = (41.6138454894+34.5862930161j)\n",
"c\n",
"power factor = 0.77\n",
"leading\n"
]
}
],
"prompt_number": 1
}
],
"metadata": {}
}
]
}
|
