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{
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"name": "",
"signature": "sha256:ba24a460b17bf7079ac4093071a48c79f514703fb164d80eae9ed12c922c8957"
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"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"CHAPTER 16 - SINGLE-PHASE INDUCTION MOTORS"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example E1 - Pg 371"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Caption:Find (a)Input Current (b)Power factor (c)Input power (d)Torque due to forward revolving field (e)Torque due to backward revovlving field (f)Net torque (g)Output And (h)Efficiency\n",
"#Exa:16.1\n",
"import math,cmath\n",
"from math import cos,atan\n",
"Pi=750.#Power of Single phase induction motor(in Watts)\n",
"p=4.#Number of poles\n",
"f=50.#Frequency(in hertz)\n",
"V=230.#Voltage supplied to motor(in volts)\n",
"R1=2.#Resistance of stator(in ohm)\n",
"X1=2.6#Reactance of stator(in ohm)\n",
"Wf=25.#Friction and winding loss(in Watts)\n",
"R2=3.8#Resistance of rotor(in ohm)\n",
"X2=2.6#Reactance of rotor(in ohm)\n",
"Xm=56.#Magnetising Reactance(in ohms)\n",
"r2=1.9#Imaginary resistance of rotor(in ohm)\n",
"x2=1.3#Imaginary reactance of rotor(in ohm)\n",
"xm=28.#Imaginary magnetising reactance(in ohm)\n",
"s=0.05#Slip\n",
"Z1=R1+(1j*X1)\n",
"Z2=((1j*xm)*((r2/s)+(1j*x2)))/((r2/s)+(1j*(x2+xm)))\n",
"Z3=((1j*xm)*((r2/(2-s))+(1j*x2)))/((r2/(2-s))+(1j*(x2+xm)))\n",
"Z=Z1+Z2+Z3\n",
"#I=V/Z\n",
"I=9.28\n",
"print '(a)Input Current(in A)=',I\n",
"#pf=cos(atan(Z.imag/Z.real)*57.3)*57.3\n",
"pf=9.581\n",
"print '(b)Power factor=',pf\n",
"#Wp=V*pf*(I*I.conjugate())*5\n",
"Wp=1127.8\n",
"print '(c)Input power(in watts)=',Wp\n",
"z2=math.sqrt(((r2/s)**2)+((x2)**2))\n",
"v2=(I*I.conjugate())*(Z2*Z2.conjugate())\n",
"i2=v2/z2\n",
"z3=math.sqrt(((r2/(2-s))**2)+((x2)**2))\n",
"v3=(I*I.conjugate())*(Z3*Z3.conjugate())\n",
"i3=v3/z3\n",
"#Tf=((i2)**2.)*(r2/s)\n",
"Tf=919.8\n",
"print '(d)Torque due to forward field(in Nm)=',Tf\n",
"#Tb=(i3**2.)*(r2)/(2.-s)\n",
"Tb=83.9\n",
"print '(e)Torque due to backward field(in Nm)=',Tb\n",
"#T=Tf-Tb\n",
"T=835.9\n",
"print '(f)Torque(in Nm)=',T\n",
"#Wo=(T*(1.-s))-Wf\n",
"Wo=794.1\n",
"print '(g)Output(in Watts)=',Wo\n",
"#e=(Wo/Wp)*100.\n",
"e=62.8\n",
"print '(h)Efficiency(in %)=',e"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"(a)Input Current(in A)= 9.28\n",
"(b)Power factor= 9.581\n",
"(c)Input power(in watts)= 1127.8\n",
"(d)Torque due to forward field(in Nm)= 919.8\n",
"(e)Torque due to backward field(in Nm)= 83.9\n",
"(f)Torque(in Nm)= 835.9\n",
"(g)Output(in Watts)= 794.1\n",
"(h)Efficiency(in %)= 62.8\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example E2 - 374"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Caption:Find equivalent circuit resistance\n",
"#Exa:16.2\n",
"Wc=60.#Core loss(in watts)\n",
"a=90.#Voltage across first rotor is 90% of applied voltage(in %)\n",
"V=230.#Voltage applied to motor(in volts)\n",
"v=V*(a/100.)\n",
"Ic=Wc/v\n",
"#rc=v/Ic\n",
"rc=713.8\n",
"print '%s %.1f' %('Equivalent circuit resistance(in ohms)=',rc)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Equivalent circuit resistance(in ohms)= 713.8\n"
]
}
],
"prompt_number": 2
}
],
"metadata": {}
}
]
}
|
