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 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Ch-4, Permanent Magnet Generators"
     ]
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.1 page 222 "
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "from math import pi, floor\n",
      "# Given data\n",
      "kf=0.12  #  in Nm/A\n",
      "V=48 #in volt\n",
      "\n",
      "#Calculations\n",
      "omega_mo=V/kf#in radian/sec\n",
      "No=omega_mo*60/(2*pi)#in rpm\n",
      "print \"No load speed in rpm =\",floor(No) "
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "No load speed in rpm = 3819.0\n"
       ]
      }
     ],
     "prompt_number": 27
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.2 page 223"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# Given data\n",
      "Tst=1.0  #  in N-m\n",
      "Ist=5.0 #in Ampere\n",
      "V=28.0 #in volt\n",
      "\n",
      "#Calculations\n",
      "kf=Tst/Ist #in Nm/A\n",
      "omega_m=V/kf#in radian/sec\n",
      "No=omega_m*60/(2*pi)#in rpm\n",
      "print \"No load speed in rpm =\", No "
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "No load speed in rpm = 1336.90152197\n"
       ]
      }
     ],
     "prompt_number": 28
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.3 page 223"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# Given data\n",
      "Ra=0.8 #in \u03a9\n",
      "Vdd=2 #in volt\n",
      "V=28 #in volt\n",
      "T1=0.3  #  in N-m\n",
      "Tst=1  #  in N-m\n",
      "Ist=5 #in Ampere\n",
      "\n",
      "#Calculations\n",
      "#We know : Tst = fi_1*Ist  and T1 = IL*fi_2\n",
      "#Deviding these two eqn we have\n",
      "IL=(T1/Tst)*Ist/0.8 #in Ampere\n",
      "Ebo=V #in volt\n",
      "NLbyNo=(V-IL*Ra-Vdd)/(0.8*Ebo) # temporary calculation for NL\n",
      "No=1337 #in rpm\n",
      "NL=NLbyNo*No #in rpm\n",
      "print \"Speed of motor in rpm =\",NL "
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Speed of motor in rpm = 1462.34375\n"
       ]
      }
     ],
     "prompt_number": 29
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.4 page 224"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# Given data\n",
      "ke=0.12 #in Nm/A\n",
      "V=48 #in volt\n",
      "Rph=0.15 #in \u03a9\n",
      "Vdd=2 #in volt\n",
      "\n",
      "#Calculations\n",
      "omega_mo=V/ke#in radian/sec\n",
      "No=omega_mo*60/(2*pi)#in rpm\n",
      "print \"No load speed in rpm =\",No \n",
      "\n",
      "Ist=(V-Vdd)/(2*Rph) #in Ampere\n",
      "Tst=ke*Ist  #  in N-m\n",
      "print \"Starting Torque  in N-m =\",Tst \n",
      "#Note : answer is wrong in the book."
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "No load speed in rpm = 3819.71863421\n",
        "Starting Torque  in N-m = 18.4\n"
       ]
      }
     ],
     "prompt_number": 30
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.5 page 225"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "# Given data\n",
      "Vs=120 #in volt\n",
      "V=60 #in volt\n",
      "Ra=2.5 #in \u03a9\n",
      "T=0.5  #  in N-m\n",
      "N=6000#in rpm\n",
      "\n",
      "#Calculations\n",
      "\n",
      "omega_mo=2*pi*N/60#in radian/sec\n",
      "ke=Vs/omega_mo #in Nm/A\n",
      "Ia=T/ke #in Ampere\n",
      "E=V-Ia*Ra #in Volt\n",
      "omega_m=E/ke#in radian/sec\n",
      "N=omega_m/(2*pi/60) #in rpm\n",
      "print \"Speed in rpm =\",N \n",
      "#Note : answer is wrong in the book because calculation is not accurate. ."
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Speed in rpm = 2672.75076525\n"
       ]
      }
     ],
     "prompt_number": 31
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.6 page 226"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "from __future__ import division\n",
      "# Given data\n",
      "lm=6*10**-3 #magnet length in m\n",
      "g=2*10**-3 #in m\n",
      "Tph=200.0 #turns\n",
      "Br=0.3 #in T\n",
      "l=50*10**-3 #in m\n",
      "n=25*10**-3 #in m\n",
      "I=10*10**-3 #in A\n",
      "N=200.0 #turns\n",
      "mo=4.0*pi*10**-7 #permittivity\n",
      "#Calculations\n",
      "Am=(2/3)*pi*(n-g-lm/2)*l #in m**2\n",
      "Ag=((2/3)*pi*(n-g/2)+2*g)*(l+2*g) #in m**2    \n",
      "Cfi=Am/Ag #unitless\n",
      "#For normal BLDG motor, HC=606 KA/M\n",
      "HC=606 #in  KA/M\n",
      "Hm=N*I/l #KA/M\n",
      "Bm=Br*(1-Hm/HC) #in T\n",
      "Mrec=(Br-Bm)*10**-3.0/(4*pi*10**-7*40) \n",
      "Pmo=mo*Mrec*Am/lm #in m-Wb/AT\n",
      "Pmo=Pmo*10**-3 #in Wb/AT\n",
      "Kc=1.05 #given constant\n",
      "g_dash=Kc*g #in m\n",
      "Rg=g_dash/mo/Am \n",
      "Bg=Cfi*Br/(1+Pmo*Rg) #in T\n",
      "Torque=2*Tph*Bg*l*n*I #in N-m\n",
      "print \"Torque per phase in N-m =\",Torque "
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Torque per phase in N-m = 0.00107194515868\n"
       ]
      }
     ],
     "prompt_number": 32
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.7 page 228"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "from math import sin, sqrt, pi\n",
      "# Given data\n",
      "P=16 #no.of poles\n",
      "slots=144 #no. of slotes\n",
      "conductors=10 #per slot\n",
      "fi=0.03 #in mb/pole\n",
      "N=375#in rpm\n",
      "\n",
      "#Calculations\n",
      "f=P*N/120 #in Hz\n",
      "print f,\"Frequency in Hz = \" \n",
      "kc=1 #for full pitcheed coil\n",
      "n=slots/P #slots per pole\n",
      "Beta=180/n #in degree\n",
      "m=n/3 #slots per pole per phase\n",
      "kd=sin(3*Beta/2*pi/180)/(m*sin(Beta/2*pi/180)) #Distribution factor\n",
      "Z=conductors*slots #total no. of conductors\n",
      "Zph=Z/3 # no. of armature per phase conductions\n",
      "Tph=Zph/2 #turns/ph\n",
      "Eph=4.44*kc*kd*f*fi*Tph #in volts\n",
      "print Eph,\"Phase Voltage in volts = \" \n",
      "VL=sqrt(3)*Eph #in volt\n",
      "print \"Line Voltage in Volts =\",VL "
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "50.0 Frequency in Hz = \n",
        "1534.13645671 Phase Voltage in volts = \n",
        "Line Voltage in Volts = 2657.20228876\n"
       ]
      }
     ],
     "prompt_number": 33
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 4.8 page 229"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "from math import cos\n",
      "# Given data\n",
      "P=4 #no.of poles\n",
      "phase=3 #no. of phase\n",
      "slots=36 #no. of stator slotes\n",
      "turns=20 #turns per coil\n",
      "conductors=10 #per slot\n",
      "fi_m=1.8 #in m wb\n",
      "N=3000#in rpm\n",
      "\n",
      "#Calculations\n",
      "f=P*N/120 #in Hz\n",
      "Tph=turns*phase*P #no. of turns per phase\n",
      "m=slots/(phase*P) #slots per pole per phase\n",
      "n=slots/P #slots per pole\n",
      "beta=180/n #in degree\n",
      "kd1=sin(3*beta/2*pi/180)/(m*sin(beta/2*pi/180)) #Distribution factor\n",
      "alfa=2*beta #in degree(Short Pitched by 2slots)\n",
      "kp1=cos(alfa/2*pi/180) #unitless\n",
      "ks1=1 #coefficient\n",
      "kn1=kd1*kp1*ks1 #winding factor\n",
      "Eq=4.44*f*fi_m*10**-3*kn1*Tph #in volts\n",
      "print \"Open Circuit Phase emf in Volts =\",Eq "
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Open Circuit Phase emf in Volts = 172.994004918\n"
       ]
      }
     ],
     "prompt_number": 34
    }
   ],
   "metadata": {}
  }
 ]
}