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{
"metadata": {
"name": "",
"signature": "sha256:9895a0f3fc78aa13cc793dfc60b4d616a3af11e4983465d122ac29be7197893e"
},
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"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 25: Elements of Electro-Mechanical Energy Conversion"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example Number 25.1, Page Number:876"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"#variable declaration\n",
"sod=15#stator-core outer diameter\n",
"sid=10.05#stator-core inner diameter\n",
"rod=10.00#rotor-core outer diameter\n",
"rid=5#rotor-core inner diameter\n",
"a=8#axial lenght of the machine\n",
"b=1.20\n",
"ur=1000\n",
"#calculations\n",
"vs=(3.14/4)*((sod*sod)-(sid*sid))*a#volume of stator-core\n",
"vr=(3.14/4)*((rod*rod)-(rid*rid))*a#volume of rotor-core\n",
"va=(3.14/4)*((sid*sid)-(rod*rod))*a#volume of air-gap in the machine\n",
"ed=(.5*b*b)/(4*3.14*math.pow(10,-7))\n",
"e=ed*va*math.pow(10,-6)\n",
"edm=(.5*b*b)/(4*3.14*math.pow(10,-7)*ur)\n",
"es=edm*vs*math.pow(10,-6)\n",
"er=edm*vr*math.pow(10,-6)\n",
"kr=(vs+vr)/vs\n",
"ke=(es+er)/e\n",
"ratio=kr/ke\n",
"eratio=e/(es+er)\n",
"\n",
"#result\n",
"print \"Energy stored in air gap= \",e,\" Joules\"\n",
"print \"Energy stored in stator-core= \",round(es,2),\" Joules\"\n",
"print \"Energy stored in rotor core= \",er,\" Joules\"\n",
"print \"Ratio of energy dtored in air-gap to that stored in the cores=\",round(eratio)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Energy stored in air gap= 3.609 Joules\n",
"Energy stored in stator-core= 0.45 Joules\n",
"Energy stored in rotor core= 0.27 Joules\n",
"Ratio of energy dtored in air-gap to that stored in the cores= 5.0\n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example Number 25.2, Page Number:877"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"#variable declaration\n",
"n=800#turns\n",
"area=5*5#cross sectional area\n",
"i=1.25#amp\n",
"x=0.25#cm\n",
"l=0.402\n",
"#calculations\n",
"p=4*3.14*10**(-7)*area*10**(-4)/(0.5*10**(-2))\n",
"l=n**2*p\n",
"em=.5*i*i*l\n",
"W=-1*0.5*n**2*4*3.14*10**(-7)*area*10**(-4)*i**2/(0.5*10**(-2))**2\n",
"\n",
"#result\n",
"print \"a)i)coil inductance=\",l,\"H\"\n",
"print \" ii)field energy stored=\",em,\"J\"\n",
"print \"b)mechanical energy output=\",W,\"NW\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"a)i)coil inductance= 0.40192 H\n",
" ii)field energy stored= 0.314 J\n",
"b)mechanical energy output= -62.8 NW\n"
]
}
],
"prompt_number": 13
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example Number 25.4, Page Number:882"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#variable declaration\n",
"lo=50#mH\n",
"xo=0.05#cm\n",
"r=0.5#ohm\n",
"x=0.075#cm\n",
"i2=3#A\n",
"x2=0.15#cm\n",
"\n",
"#calculation\n",
"l1=2*lo/(1+(x/xo))\n",
"lambda1=l1*i2*10**(-3)\n",
"W=0.5*l1*i2**2*10**(-3)\n",
"l2=2*lo/(1+(x2/xo))\n",
"lambda2=l2*i2*10**(-3)\n",
"w2=0.5*i2*(lambda1-lambda2)\n",
"\n",
"#result\n",
"print \"a)magnetic stored energy=\",W,\"J\"\n",
"print \"b)change in magnetic stored energy=\",w2,\"J\""
],
"language": "python",
"metadata": {},
"outputs": []
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example Number 25.5, Page Number:883"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#variable declaration\n",
"rc=0.5#ohm\n",
"v=3#V\n",
"i=6#A\n",
"l1=40#mH\n",
"l2=25#mH\n",
"wfld=0.5*l2*i*i*0.001\n",
"delE=0.5*i*i*0.001*(l1-l2)\n",
"\n",
"#result\n",
"print \"a)magnetic stored energy=\",wfld,\"J\"\n",
"print \"b)change in magnetic store energy=\",delE,\"J\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"a)magnetic stored energy= 0.45 J\n",
"b)change in magnetic store energy= 0.27 J\n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "code",
"collapsed": false,
"input": [],
"language": "python",
"metadata": {},
"outputs": []
}
],
"metadata": {}
}
]
}
|
