diff options
Diffstat (limited to 'Fundamentals_of_Electrical_Machines/CH_4.ipynb')
| -rwxr-xr-x | Fundamentals_of_Electrical_Machines/CH_4.ipynb | 499 |
1 files changed, 499 insertions, 0 deletions
diff --git a/Fundamentals_of_Electrical_Machines/CH_4.ipynb b/Fundamentals_of_Electrical_Machines/CH_4.ipynb new file mode 100755 index 00000000..76dec5aa --- /dev/null +++ b/Fundamentals_of_Electrical_Machines/CH_4.ipynb @@ -0,0 +1,499 @@ +{
+ "metadata": {
+ "name": ""
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+ {
+ "cells": [
+ {
+ "cell_type": "heading",
+ "level": 1,
+ "metadata": {},
+ "source": [
+ "CHAPTER 4: DIRECT CURRENT GENERATORS"
+ ]
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 4.1, Page number 143"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "from sympy import *\n",
+ "\n",
+ "#Variable declaration\n",
+ "N = 100.0 #Number of turns\n",
+ "\n",
+ "#Calculation\n",
+ "t = Symbol('t')\n",
+ "e = N*diff(0.05*sin(314*t), t, 1)\n",
+ "\n",
+ "#Result\n",
+ "print('Induced voltage at the coil terminals , e = ' + repr(e) + ' V')"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "Induced voltage at the coil terminals , e = 1570.0*cos(314*t) V\n"
+ ]
+ }
+ ],
+ "prompt_number": 1
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 4.2, Page number 145"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "l = 0.65 #Length of conductor(m)\n",
+ "v = 35.0 #Speed of conductor(m/s)\n",
+ "B = 0.8 #Magnetic flux density(Tesla)\n",
+ "\n",
+ "#Calculation\n",
+ "e = B*l*v #Induced voltage at the conductor(V)\n",
+ "\n",
+ "#Result\n",
+ "print('Induced voltage at the conductor , e = %.1f V' %e)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "Induced voltage at the conductor , e = 18.2 V\n"
+ ]
+ }
+ ],
+ "prompt_number": 1
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 4.3, Page number 145"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "import math\n",
+ "\n",
+ "#Variable declaration\n",
+ "l = 1.5 #Length of conductor(m)\n",
+ "v = 20.0 #Velocity of conductor(m/s)\n",
+ "theta = 35.0*math.pi/180 #Angle(radians)\n",
+ "B = 0.9 #Magnetic flux density(Wb/m^2)\n",
+ "\n",
+ "#Calculation\n",
+ "e = B*l*v*math.sin(theta) #Induced voltage at the conductor(V)\n",
+ "\n",
+ "#Result\n",
+ "print('Induced voltage at the conductor , e = %.1f V' %e)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "Induced voltage at the conductor , e = 15.5 V\n"
+ ]
+ }
+ ],
+ "prompt_number": 1
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 4.4, Page number 152-153"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "P = 4.0 #Number of poles\n",
+ "S = 40.0 #Number of slots\n",
+ "C = 10.0 #Number of conductors per slot\n",
+ "phi = 0.02 #Flux per pole(Wb)\n",
+ "N = 1200.0 #Speed(rpm)\n",
+ "\n",
+ "#Calculation\n",
+ "Z = S*C #Total number of conductors\n",
+ "A = 2.0 #Number of parallel paths for Wave winding\n",
+ "E_g = P*phi*Z*N/(60*A) #Generated emf(V)\n",
+ "\n",
+ "#Result\n",
+ "print('Generated emf , E_g = %.f V' %E_g)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "Generated emf , E_g = 320 V\n"
+ ]
+ }
+ ],
+ "prompt_number": 1
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 4.5, Page number 153"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "import math\n",
+ "\n",
+ "#Variable declaration\n",
+ "P = 6.0 #Number of poles\n",
+ "Z = 600.0 #Number of conductors\n",
+ "phi = 0.05 #Flux per pole(Wb)\n",
+ "N = 1000.0 #Speed of generator(rpm)\n",
+ "I_a = 120.0 #Current supplied by generator(A)\n",
+ "\n",
+ "#Calculation\n",
+ "A = P #Number of parallel paths for lap winding\n",
+ "E_g = P*phi*Z*N/(60*A) #Generated voltage(V)\n",
+ "T_em = (P*Z*phi)/(2*math.pi*A)*I_a #Electromagnetic torque(N-m)\n",
+ "\n",
+ "\n",
+ "#Result\n",
+ "print('Generated voltage , E_g = %.f V' %E_g)\n",
+ "print('Electromagnetic torque , T_em = %.2f N-m' %T_em)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "Generated voltage , E_g = 500 V\n",
+ "Electromagnetic torque , T_em = 572.96 N-m\n"
+ ]
+ }
+ ],
+ "prompt_number": 1
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 4.6, Page number 156"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "V_t = 220.0 #Shunt generator voltage(V)\n",
+ "I_L = 250.0 #Load current(A)\n",
+ "R_sh = 50.0 #Shunt field resistance(ohm)\n",
+ "R_a = 0.02 #Armature resistance(ohm)\n",
+ "\n",
+ "#Calculation\n",
+ "I_sh = V_t/R_sh #Shunt field current(A)\n",
+ "I_a = I_L+I_sh #Armature current(A)\n",
+ "E_g = V_t+I_a*R_a #Generated voltage(V)\n",
+ "\n",
+ "#Result\n",
+ "print('Generated voltage , E_g = %.2f V' %E_g)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "Generated voltage , E_g = 225.09 V\n"
+ ]
+ }
+ ],
+ "prompt_number": 1
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 4.7, Page number 158-160"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "E = 25.0 #Power of compound generator(kW)\n",
+ "V_t = 220.0 #Terminal voltage(V)\n",
+ "R_a = 0.07 #Armature resistance(ohm)\n",
+ "R_se = 0.05 #Series resistance(ohm)\n",
+ "R_sh = 55.0 #Shunt field resistance(ohm)\n",
+ "V_brush = 1.0 #Voltage drop per brush(V)\n",
+ "\n",
+ "#Calculation\n",
+ "I_L = E*10**3/V_t #Load current in A\n",
+ "I_sh = V_t/R_sh #Shunt field current(A)\n",
+ "I_a = I_sh+I_L #Armature current(A)\n",
+ "#For case(i)\n",
+ "E_g1 = V_t+I_a*(R_a+R_se)+2*V_brush #Generated emf(V)\n",
+ "#For case(ii)\n",
+ "V_ab = V_t+I_L*R_se #Voltage across the shunt field(V)\n",
+ "I_sh2 = V_ab/R_sh #Current in the shunt field(A)\n",
+ "I_a2 = I_sh2+I_L #Armature current(A)\n",
+ "E_g2 = V_ab+I_a2*R_a+2*V_brush #Generated emf(V)\n",
+ "\n",
+ "#Result\n",
+ "print('(i) Generated emf when generator is connected in long shunt , E_g = %.f V' %E_g1)\n",
+ "print('(ii) Generated emf when generator is connected in short shunt , E_g = %.1f V' %E_g2)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "(i) Generated emf when generator is connected in long shunt , E_g = 236 V\n",
+ "(ii) Generated emf when generator is connected in short shunt , E_g = 235.9 V\n"
+ ]
+ }
+ ],
+ "prompt_number": 1
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 4.8, Page number 160-161"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "V_t = 220.0 #Shunt generator voltage(V)\n",
+ "I_L = 146.0 #Current delivered by generator(A)\n",
+ "R_sh = 55.0 #Shunt field resistance(ohm)\n",
+ "R_a = 0.012 #Armature resistance(ohm)\n",
+ "R_se = 0.02 #Series field resistance(ohm)\n",
+ "R_di = 0.03 #Diverter field resistance(ohm)\n",
+ "\n",
+ "#Calculation\n",
+ "I_sh = V_t/R_sh #Shunt field current(A)\n",
+ "I_a = I_L+I_sh #Armature current(A)\n",
+ "R_com = R_se*R_di/(R_se+R_di) #Combined resistance(ohm)\n",
+ "E_g = V_t+I_a*(R_a+R_com) #Generated voltage(V)\n",
+ "P_lsd = I_a**2*R_com #Power loss in series field and diverter(W)\n",
+ "P_la = I_a**2*R_a #Power loss in the armature circuit resistance(W)\n",
+ "P_lsh = V_t*I_sh #Power loss in shunt field resistance(W)\n",
+ "P_dl = I_L*V_t #Power delivered(W)\n",
+ "\n",
+ "#Result\n",
+ "print('Generated voltage , E_g = %.1f V' %E_g)\n",
+ "print('Power loss in the series field and diverter , P_lsd = %.1f W' %P_lsd)\n",
+ "print('Power loss in the armature circuit resistance , P_la = %.1f W' %P_la)\n",
+ "print('Power loss in the shunt field resistance , P_lsh = %.f W' %P_lsh)\n",
+ "print('Power delivered to the load , P_dl = %.f W' %P_dl)\n",
+ "print('\\nNOTE : ERROR : Shunt field resistance is taken as 50 ohm while solving I_sh in textbook but it is 55 ohm as per textbook question')"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "Generated voltage , E_g = 223.6 V\n",
+ "Power loss in the series field and diverter , P_lsd = 270.0 W\n",
+ "Power loss in the armature circuit resistance , P_la = 270.0 W\n",
+ "Power loss in the shunt field resistance , P_lsh = 880 W\n",
+ "Power delivered to the load , P_dl = 32120 W\n",
+ "\n",
+ "NOTE : ERROR : Shunt field resistance is taken as 50 ohm while solving I_sh in textbook but it is 55 ohm as per textbook question\n"
+ ]
+ }
+ ],
+ "prompt_number": 1
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 4.9, Page number 169"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "P = 4.0 #Number of poles\n",
+ "Z = 500.0 #Number of conductors\n",
+ "I_a = 30.0 #Current delivered by generator(A)\n",
+ "alpha = 6.0 #Angle at which brushes are displaced angle(degree)\n",
+ "\n",
+ "#Calculation\n",
+ "A = 2.0 #Number of parallel paths for Wave winding\n",
+ "I_c = I_a/A #Current per conductor(A)\n",
+ "#For case(i)\n",
+ "AT_d = Z*I_c*alpha/360 #Demagnetizing ampere-turns per pole(At)\n",
+ "#For case(ii)\n",
+ "AT_c = Z*I_c*((1/(2*P))-(alpha/360)) #Cross magnetizing ampere-turns per pole(At)\n",
+ "\n",
+ "#Result\n",
+ "print('(i) Demagnetizing ampere-turns , AT_d = %.f At' %AT_d)\n",
+ "print('(ii) Cross-magnetizing ampere-turns , AT_c = %.1f At' %AT_c)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "(i) Demagnetizing ampere-turns , AT_d = 125 At\n",
+ "(ii) Cross-magnetizing ampere-turns , AT_c = 812.5 At\n"
+ ]
+ }
+ ],
+ "prompt_number": 1
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 4.10, Page number 176"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "Power = 12.0 #Power(kW)\n",
+ "P = 4.0 #Number of poles\n",
+ "Z = 500.0 #Number of conductors\n",
+ "V_t = 250.0 #Generator voltage(V)\n",
+ "N = 1000.0 #Speed(rpm)\n",
+ "P_cu = 600 #Full load copper loss(W)\n",
+ "brush_drop = 2.0 #Total brush drop(V)\n",
+ "\n",
+ "#Calculation\n",
+ "A = P #Number of parallel paths for lap winding\n",
+ "I_a = Power*10**3/V_t #Armature current(A)\n",
+ "R_a = P_cu/I_a**2 #Armature resistance(ohm)\n",
+ "E_g = V_t+I_a*R_a+brush_drop #Generated voltage(V)\n",
+ "phi = E_g*60*A/(P*Z*N) #Flux per pole(Wb)\n",
+ "\n",
+ "#Result\n",
+ "print('Flux per pole , \u03a6 = %.3f Wb' %phi)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "Flux per pole , \u03a6 = 0.032 Wb\n"
+ ]
+ }
+ ],
+ "prompt_number": 1
+ },
+ {
+ "cell_type": "heading",
+ "level": 2,
+ "metadata": {},
+ "source": [
+ "Example 4.11, Page number 176-177"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "collapsed": false,
+ "input": [
+ "#Variable declaration\n",
+ "P = 4.0 #Number of poles\n",
+ "I_L = 25.0 #Current delivered by generator(A)\n",
+ "V_t = 230.0 #Generator terminal voltage(V)\n",
+ "R_a = 0.2 #Armature resistance(ohm)\n",
+ "R_sh = 55.0 #Shunt field resistance(ohm)\n",
+ "V_brush = 1.0 #Voltage drop per brush(V)\n",
+ "\n",
+ "#Calculation\n",
+ "I_sh = V_t/R_sh #Shunt field current(A)\n",
+ "I_a = I_L+I_sh #Armature current(A)\n",
+ "E_g = V_t+I_a*R_a+2*V_brush #Induced voltage(V)\n",
+ "P_arm = E_g*I_a #Power generated in armature(W)\n",
+ "P_L = V_t*I_L #Power absorbed by load(W)\n",
+ "n = (P_L/P_arm)*100 #Efficiency(percent)\n",
+ "\n",
+ "#Result\n",
+ "print('Induced voltage , E_g = %.1f V' %E_g)\n",
+ "print('Efficiency of generator , \u03b7 = %.1f percent' %n)"
+ ],
+ "language": "python",
+ "metadata": {},
+ "outputs": [
+ {
+ "output_type": "stream",
+ "stream": "stdout",
+ "text": [
+ "Induced voltage , E_g = 237.8 V\n",
+ "Efficiency of generator , \u03b7 = 82.8 percent\n"
+ ]
+ }
+ ],
+ "prompt_number": 1
+ }
+ ],
+ "metadata": {}
+ }
+ ]
+}
\ No newline at end of file |