summaryrefslogtreecommitdiff
path: root/Electric_Machinery_and_Transformers/CHAP_6.ipynb
blob: 8d4aa0493a3c93f11346567215f8246547d69d0f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
{
 "metadata": {
  "name": ""
 },
 "nbformat": 3,
 "nbformat_minor": 0,
 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "CHAPTER 6: AC DYNAMO VOLTAGE RELATIONS-ALTERNATORS"
     ]
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 6.1, Page number 160"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Variable declaration\n",
      "kVA = 1000.0   #Rating of the 3-phase alternator(kVA) \n",
      "V_L = 4600.0   #Rated line voltage(V)\n",
      "R_a = 2.0      #Armature resistance per phase(ohm)\n",
      "X_s = 20.0     #Synchronous armature reactance per phase(ohm)\n",
      "pf_a = 1.0     #Unity power factor\n",
      "pf_b = 0.75    #Lagging power factor\n",
      "\n",
      "#Calculation\n",
      "V_P = V_L/3**0.5            #Phase voltage(V)\n",
      "I_P = kVA*1000/(3*V_P)      #Phase current(A)\n",
      "I_a  = I_P                  #Armature current(A)\n",
      "#Case(a)\n",
      "E_g_a = complex((V_P+I_a*R_a),(I_a*X_s))                        #Full-load generated voltage per phase(V/phase)\n",
      "#Case(b)\n",
      "sin_theta_b = (1-pf_b**2)**0.5                                  #Sin of angle of theta_b\n",
      "E_g_b = complex((V_P*pf_b+ I_a*R_a),(V_P*sin_theta_b+I_a*X_s))  #Full-load generated voltage per phase(V/phase)\n",
      "\n",
      "#Result\n",
      "print('Case(a): Full-load generated voltage per phase at unity PF , E_g = %d V/phase' %(abs(E_g_a)))\n",
      "print('Case(b): Full-load generated voltage per phase at 0.75 PF lagging , E_g = %d V/phase' %(abs(E_g_b)))\n",
      "print('\\nNOTE: \u221a3 value is taken as %f instead of 1.73 as in textbook so slight variations in the obtained answer' %(3**0.5))"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Case(a): Full-load generated voltage per phase at unity PF , E_g = 3840 V/phase\n",
        "Case(b): Full-load generated voltage per phase at 0.75 PF lagging , E_g = 4820 V/phase\n",
        "\n",
        "NOTE: \u221a3 value is taken as 1.732051 instead of 1.73 as in textbook so slight variations in the obtained answer\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 6.2, Page number 161"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Variable declaration\n",
      "kVA = 1000.0   #Rating of the 3-phase alternator(kVA) \n",
      "V_L = 4600.0   #Rated line voltage(V)\n",
      "R_a = 2.0      #Armature resistance per phase(ohm)\n",
      "X_s = 20.0     #Synchronous armature reactance per phase(ohm)\n",
      "pf_a = 0.75    #Leading power factor\n",
      "pf_b = 0.40    #Leading power factor\n",
      "\n",
      "#Calculation\n",
      "V_P = V_L/3**0.5            #Phase voltage(V)\n",
      "I_P = kVA*1000/(3*V_P)      #Phase current(A)\n",
      "I_a  = I_P                  #Armature current(A)\n",
      "#Case(a)\n",
      "sin_theta_a = (1-pf_a**2)**0.5                                  #Sin of angle of theta_a\n",
      "E_g_a = complex((V_P*pf_a+I_a*R_a),(V_P*sin_theta_a-I_a*X_s))   #Full-load generated voltage per phase(V/phase)\n",
      "#Case(b)\n",
      "sin_theta_b = (1-pf_b**2)**0.5                                  #Sin of angle of theta_b\n",
      "E_g_b = complex((V_P*pf_b+ I_a*R_a),(V_P*sin_theta_b+-I_a*X_s))  #Full-load generated voltage per phase(V/phase)\n",
      "\n",
      "#Result\n",
      "print('Case(a): Full-load generated voltage per phase at 0.75 PF leading , E_g = %d V/phase' %(abs(E_g_a)))\n",
      "print('Case(b): Full-load generated voltage per phase at 0.40 PF leading , E_g = %d V/phase' %(abs(E_g_b)))\n",
      "print('\\nNOTE: \u221a3 value is taken as %f instead of 1.73 as in textbook so slight variations in the obtained answer' %(3**0.5))"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Case(a): Full-load generated voltage per phase at 0.75 PF leading , E_g = 2366 V/phase\n",
        "Case(b): Full-load generated voltage per phase at 0.40 PF leading , E_g = 1315 V/phase\n",
        "\n",
        "NOTE: \u221a3 value is taken as 1.732051 instead of 1.73 as in textbook so slight variations in the obtained answer\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 6.3, Page number 162"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "V_P = 2655.0     #Phase voltage(V) \n",
      "E_g_a1 = 4820.0  #Full-load generated voltage per phase at 0.75 PF lagging(V/phase)\n",
      "E_g_b1 = 3840.0  #Full-load generated voltage per phase at unity PF(V/phase)\n",
      "E_g_a2 = 2366.0  #Full-load generated voltage per phase at 0.75 PF leading(V/phase)\n",
      "E_g_b2 = 1315.0  #Full-load generated voltage per phase at 0.40 PF leading(V/phase)\n",
      "\n",
      "#Calculation\n",
      "VR_a = (E_g_a1-V_P)/V_P*100     #Voltage regulation at 0.75 PF lagging(percent)\n",
      "VR_b = (E_g_b1-V_P)/V_P*100     #Voltage regulation at unity PF(percent)\n",
      "VR_c = (E_g_a2-V_P)/V_P*100     #Voltage regulation at 0.75 PF leading(percent)\n",
      "VR_d = (E_g_b2-V_P)/V_P*100     #Voltage regulation at 0.75 PF leading(percent)\n",
      "\n",
      "#Result\n",
      "print('Case(a): Voltage regulation at 0.75 PF lagging , VR = %.1f percent' %VR_a)\n",
      "print('Case(b): Voltage regulation at unity PF , VR = %.1f percent' %VR_b)\n",
      "print('Case(c): Voltage regulation at 0.75 PF leading , VR = %.2f percent' %VR_c)\n",
      "print('Case(d): Voltage regulation at 0.40 PF leading , VR = %.1f percent' %VR_d)\n",
      "print('\\nNOTE: \u221a3 value is taken as %f instead of 1.73 as in textbook so slight variations in the obtained answer' %(3**0.5))"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Case(a): Voltage regulation at 0.75 PF lagging , VR = 81.5 percent\n",
        "Case(b): Voltage regulation at unity PF , VR = 44.6 percent\n",
        "Case(c): Voltage regulation at 0.75 PF leading , VR = -10.89 percent\n",
        "Case(d): Voltage regulation at 0.40 PF leading , VR = -50.5 percent\n",
        "\n",
        "NOTE: \u221a3 value is taken as 1.732051 instead of 1.73 as in textbook so slight variations in the obtained answer\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 6.4, Page number 168"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Variable declaration\n",
      "kVA = 100.0    #Rating of the 3-phase alternator(kVA)\n",
      "V_L = 1100.0   #Line voltage of the 3-phase alternator(V)\n",
      "E_gp1 = 6.0    #DC voltage between lines in dc resistance test(V)\n",
      "I_a1 = 10.0    #DC current in lines dc resistance test(A)\n",
      "pf_1 = 0.8     #Lagging power factor\n",
      "pf_2 = 0.8     #Leading power factor\n",
      "E_gp2 = 420.0  #Voltage between lines in open-circuit test(V)\n",
      "I_f2 = 12.5    #DC Field current in open-circuit test(A)\n",
      "I_f3 = 12.5    #DC Field current in short-circuit test(A)\n",
      "\n",
      "#Calculation\n",
      "#Case(a)\n",
      "I_a_rated = kVA*1000/(V_L*3**0.5)      #Rated current per phase(A)\n",
      "I_a = 3**0.5*I_a_rated                 #Rated Line current(A)\n",
      "V_l = E_gp1\n",
      "R_dc = V_l/(2*I_a1)                    #Effective dc armature resistance(ohm/winding)\n",
      "R_ac = R_dc*1.5                        #Effective ac armature resistance(ohm/phase)\n",
      "R_a = R_ac                             #Effective ac armature resistance from dc resistance test(ohm/phase)\n",
      "Z_p = E_gp2/I_a                        #Synchronous impedance per phase(ohm/phase)\n",
      "X_s = (Z_p**2-R_a**2)**0.5             #Synchronous reactance per phase(ohm/phase)\n",
      "#Case(b)\n",
      "V_p = V_L/3**0.5                       #Phase voltage(V/phase)\n",
      "V_fl = V_p                             #Full-load voltage(V/phase)\n",
      "sin_theta_1 = (1-pf_1**2)**0.5         #Sin value of theta 1\n",
      "E_gp_lag = complex((V_p*pf_1+I_a_rated*R_a),(V_p*sin_theta_1+I_a_rated*X_s))  #Generated voltage per phase at 0.8 PF lagging(V/phase)\n",
      "V_nl_lag = abs(E_gp_lag)                    #No-load voltage(V/phase)\n",
      "VR1 = (V_nl_lag-V_fl)/V_fl*100              #Voltage regulation at 0.8 PF lagging(%)\n",
      "sin_theta_2 = (1-pf_2**2)**0.5              #Sin value of theta 2\n",
      "E_gp_lead = complex((V_p*pf_2+I_a_rated*R_a),(V_p*sin_theta_2-I_a_rated*X_s))  #Generated voltage per phase at 0.8 PF leading(V/phase)\n",
      "V_nl_lead = abs(E_gp_lead)                  #No-load voltage(V/phase)\n",
      "VR2 = (V_nl_lead-V_fl)/V_fl*100             #Voltage regulation at 0.8 PF leading(%)\n",
      "\n",
      "#Result\n",
      "print('Case(a): Effective resistance per phase , R_ac = %.2f \u03a9/phase' %R_ac)\n",
      "print('         Synchronous impedance per phase , Z_p = %.2f \u03a9/phase' %Z_p)\n",
      "print('         Synchronous reactance per phase , X_s = %.1f \u03a9/phase' %X_s)\n",
      "print('Case(b): Voltage regulation at 0.8 PF lagging = %.f percent' %VR1)\n",
      "print('         Voltage regulation at 0.8 PF leading = %.1f percent' %VR2)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Case(a): Effective resistance per phase , R_ac = 0.45 \u03a9/phase\n",
        "         Synchronous impedance per phase , Z_p = 4.62 \u03a9/phase\n",
        "         Synchronous reactance per phase , X_s = 4.6 \u03a9/phase\n",
        "Case(b): Voltage regulation at 0.8 PF lagging = 29 percent\n",
        "         Voltage regulation at 0.8 PF leading = -13.4 percent\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 6.5, Page number 169"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Variable declaration\n",
      "kVA = 100.0    #Rating of the 3-phase alternator(kVA)\n",
      "V_L = 1100.0   #Line voltage of the 3-phase alternator(V)\n",
      "E_gp1 = 6.0    #DC voltage between lines in dc resistance test(V)\n",
      "I_a1 = 10.0    #DC current in lines dc resistance test(A)\n",
      "pf_1 = 0.8     #Lagging power factor\n",
      "pf_2 = 0.8     #Leading power factor\n",
      "E_gp2 = 420.0  #Voltage between lines in open-circuit test(V)\n",
      "I_f2 = 12.5    #DC Field current in open-circuit test(A)\n",
      "I_f3 = 12.5    #DC Field current in short-circuit test(A)\n",
      "\n",
      "#Calculation\n",
      "#Case(a)\n",
      "I_a_rated = kVA*1000/(V_L*3**0.5)      #Rated current per phase(A)\n",
      "I_L = I_a_rated                        #Rated Line current(A)\n",
      "I_p = I_L/3**0.5                       #Phase current(A)\n",
      "I_a = I_p                              #Rated Line current(A)\n",
      "Z_s = E_gp2/I_p                        #Synchronous impedance per phase(ohm/phase)\n",
      "V_l = E_gp1\n",
      "R_dc = V_l/(2*I_a1)                    #Effective dc armature resistance(ohm/winding)\n",
      "R_ac = R_dc*1.5                        #Effective ac armature resistance(ohm/phase)\n",
      "R_eff = 3*R_ac                         #Effective resistance(ohm/phase)\n",
      "R_a = R_eff\n",
      "X_s = (Z_s**2-R_eff**2)**0.5           #Synchronous reactance per phase(ohm/phase)\n",
      "#Case(b)\n",
      "V_p = V_L                              #Phase voltage(V/phase)\n",
      "V_fl = V_p                             #Full-load voltage(V/phase)\n",
      "sin_theta_1 = (1-pf_1**2)**0.5         #Sin value of theta 1\n",
      "E_gp_lag = complex((V_p*pf_1+I_a*R_a),(V_p*sin_theta_1+I_a*X_s))  #Generated voltage per phase at 0.8 PF lagging(V/phase)\n",
      "V_nl_lag = abs(E_gp_lag)                    #No-load voltage(V/phase)\n",
      "VR1 = (V_nl_lag-V_fl)/V_fl*100              #Voltage regulation at 0.8 PF lagging(%)\n",
      "sin_theta_2 = (1-pf_2**2)**0.5              #Sin value of theta 2\n",
      "E_gp_lead = complex((V_p*pf_2+I_a*R_a),(V_p*sin_theta_2-I_a*X_s))  #Generated voltage per phase at 0.8 PF leading(V/phase)\n",
      "V_nl_lead = abs(E_gp_lead)                  #No-load voltage(V/phase)\n",
      "VR2 = (V_nl_lead-V_fl)/V_fl*100             #Voltage regulation at 0.8 PF leading(%)\n",
      "\n",
      "print('Case(a): Effective resistance per phase , R_eff = %.2f \u03a9/phase' %R_eff)\n",
      "print('         Synchronous impedance per phase , Z_s = %.2f \u03a9/phase' %Z_s)\n",
      "print('         Synchronous reactance per phase , X_s = %.1f \u03a9/phase' %X_s)\n",
      "print('Case(b): Voltage regulation at 0.8 PF lagging = %.f percent' %VR1)\n",
      "print('         Voltage regulation at 0.8 PF leading = %.1f percent' %VR2)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Case(a): Effective resistance per phase , R_eff = 1.35 \u03a9/phase\n",
        "         Synchronous impedance per phase , Z_s = 13.86 \u03a9/phase\n",
        "         Synchronous reactance per phase , X_s = 13.8 \u03a9/phase\n",
        "Case(b): Voltage regulation at 0.8 PF lagging = 29 percent\n",
        "         Voltage regulation at 0.8 PF leading = -13.4 percent\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 6.6, Page number 172"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#Variable declaration\n",
      "E_L = 11000.0    #Line voltage generated(V)\n",
      "kVA = 165000.0   #Rating of the alternator(kVA)\n",
      "Z_p = 1.0        #Synchronous reactance(ohm)\n",
      "R_p = 0.1        #Armature resistance(ohm/phase)\n",
      "Z_r = 0.8        #Reactor reactance(ohm/phase)\n",
      "\n",
      "#Calculation\n",
      "E_p = E_L/3**0.5              #Rated phase voltage(V)\n",
      "I_p = kVA*1000/(3*E_p)        #Rated current per phase(A)\n",
      "#Case(a)\n",
      "I_max_a = E_p/R_p             #Maximum short-circuit current(A)\n",
      "overload_a = I_max_a/I_p      #Overload\n",
      "#Case(b)\n",
      "I_steady = E_p/Z_p            #Sustained short-circuit current(A)\n",
      "overload_b = I_steady/I_p     #Overload\n",
      "#Case(c)\n",
      "Z_t = complex(R_p,Z_r)        #Total reactance per phase(ohm)\n",
      "I_max_c = E_p/abs(Z_t)        #Maximum short-circuit current(A)\n",
      "overload_c = abs(I_max_c)/I_p #Overload\n",
      "\n",
      "#Result\n",
      "print('Case(a): Maximum short-circuit current at instant of short-circuit , I_max = %.f A' %I_max_a)\n",
      "print('         Overload = %.1f * rated current' %overload_a)\n",
      "print('Case(b): Sustained short-circuit current , I_steady = %.f A' %I_steady)\n",
      "print('         Overload = %.2f * rated current' %overload_b)\n",
      "print('Case(c): Maximum short-circuit current with reactors , I_max = %.f A' %I_max_c)\n",
      "print('         Overload = %.3f * rated current' %overload_c)\n",
      "print('\\nNOTE: \u221a3 value is taken as %f instead of 1.73 as in textbook so slight variations in the obtained answer' %(3**0.5))"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Case(a): Maximum short-circuit current at instant of short-circuit , I_max = 63509 A\n",
        "         Overload = 7.3 * rated current\n",
        "Case(b): Sustained short-circuit current , I_steady = 6351 A\n",
        "         Overload = 0.73 * rated current\n",
        "Case(c): Maximum short-circuit current with reactors , I_max = 7877 A\n",
        "         Overload = 0.910 * rated current\n",
        "\n",
        "NOTE: \u221a3 value is taken as 1.732051 instead of 1.73 as in textbook so slight variations in the obtained answer\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 6.7, Page number 174"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import math\n",
      "import cmath\n",
      "\n",
      "#Variable declaration\n",
      "kVA = 100.0    #Rating of the 3-phase alternator(kVA)\n",
      "V_L = 1100.0   #Line voltage of the 3-phase alternator(V)\n",
      "E_gp1 = 6.0    #DC voltage between lines in dc resistance test(V)\n",
      "I_a1 = 10.0    #DC current in lines dc resistance test(A)\n",
      "pf = 0.8       #Lagging power factor\n",
      "E_gp2 = 420.0  #Voltage between lines in open-circuit test(V)\n",
      "I_f2 = 12.5    #DC Field current in open-circuit test(A)\n",
      "I_f3 = 12.5    #DC Field current in short-circuit test(A)\n",
      "I_L = 52.5     #Rated line current(A)\n",
      "I_a = I_L      #Rated current per phase(A)\n",
      "E_gp = complex(532,623)  #Generated voltage at 0.8 PF lagging(V/phase)\n",
      "X_s = 4.6      #Synchronous reactance per phase(ohm/phase)\n",
      "V_p = 635.0    #Phase voltage(V)\n",
      "\n",
      "#Calculation\n",
      "#Case(a)\n",
      "P_T = 3**0.5*V_L*I_L*pf                                    #Total output 3-phase power(W)\n",
      "#Case(b)\n",
      "P_p_b = P_T*10**-3/3.0                                     #Total output 3-phase power per phase(W)\n",
      "#Case(d)\n",
      "theta = math.acos(0.8)*180/math.pi                         #Phase angle of PF(degree)\n",
      "theta_plus_deba = cmath.phase(E_gp)*180/math.pi            #Phase angle of E_gp(degrees)\n",
      "deba = theta_plus_deba-theta                               #Torque angle(degrees)\n",
      "#Case(e)\n",
      "P_p_e = abs(E_gp)*10**-3/X_s*V_p*math.sin(deba*math.pi/180)         #Approximate output power per phase(W)\n",
      "#Case(f)\n",
      "P_p_f = abs(E_gp)*10**-3*I_a*math.cos(theta_plus_deba*math.pi/180)  #Approximate output power per phase(W)\n",
      "\n",
      "#Result\n",
      "print('Case(a): Total output 3-phase power , P_T = %.f W' %P_T)\n",
      "print('Case(b): Output power per phase , P_p = %.2f kW' %P_p_b)\n",
      "print('Case(c): Generated voltage , E_gp = %.1f\u2220%.1f\u00b0 V' %(abs(E_gp),cmath.phase(E_gp)*180/math.pi))\n",
      "print('Case(d): Torque angle , \u03b4 = %.2f\u00b0 ' %deba)\n",
      "print('Case(e): Approximate output power per phase , P_p = %.f W' %P_p_e)\n",
      "print('Case(f): Approximate output power per phase , P_p = %.f W' %P_p_f)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Case(a): Total output 3-phase power , P_T = 80021 W\n",
        "Case(b): Output power per phase , P_p = 26.67 kW\n",
        "Case(c): Generated voltage , E_gp = 819.2\u222049.5\u00b0 V\n",
        "Case(d): Torque angle , \u03b4 = 12.64\u00b0 \n",
        "Case(e): Approximate output power per phase , P_p = 25 W\n",
        "Case(f): Approximate output power per phase , P_p = 28 W\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 6.8, Page number 174"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import math\n",
      "\n",
      "#Variable declaration\n",
      "E_g = 819.0     #Magnitude of generated voltage(V)\n",
      "V_p = 635.0     #Phase voltage(V)\n",
      "X_s = 4.6       #Synchronous reactance per phase(ohm/phase)\n",
      "S = 1200.0      #Synchronous speed(rpm)\n",
      "delta = 12.64   #Angle(degree)\n",
      "\n",
      "#Calculation\n",
      "#Case(a)\n",
      "T_p_a = 7.04*E_g*V_p*math.sin(delta*math.pi/180)/(S*X_s)  #Output torque per phase(lb-ft)\n",
      "T_3ph_a = 3*T_p_a                                         #Total output torque(lb-ft)\n",
      "#Case(b)\n",
      "omega = S*2*math.pi/60                                    #Speed(rad/s)\n",
      "T_p_b = E_g*V_p*math.sin(delta*math.pi/180)/(omega*X_s)   #Output torque per phase(N-m)\n",
      "T_3ph_b = 3*T_p_b                                         #Total output torque(N-m)\n",
      "#Case(c)\n",
      "T_p_c = T_p_a*1.356                                       #Output torque per phase(N-m)\n",
      "T_3ph_c = 3.0*T_p_c                                       #Total output torque(N-m)\n",
      "\n",
      "#Result\n",
      "print('Case(a): Output torque per phase , T_p = %.f lb-ft' %T_p_a)\n",
      "print('         Total output torque , T_3\u03c6 = %.f lb-ft' %T_3ph_a)\n",
      "print('Case(b): Output torque per phase , T_p = %.f N-m' %T_p_b)\n",
      "print('         Total output torque , T_3\u03c6 = %.f N-m' %T_3ph_b)\n",
      "print('Case(c): Output torque per phase , T_p = %.f N-m' %T_p_c)\n",
      "print('         Total output torque , T_3\u03c6 = %.f N-m' %T_3ph_c)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Case(a): Output torque per phase , T_p = 145 lb-ft\n",
        "         Total output torque , T_3\u03c6 = 435 lb-ft\n",
        "Case(b): Output torque per phase , T_p = 197 N-m\n",
        "         Total output torque , T_3\u03c6 = 591 N-m\n",
        "Case(c): Output torque per phase , T_p = 197 N-m\n",
        "         Total output torque , T_3\u03c6 = 590 N-m\n"
       ]
      }
     ],
     "prompt_number": 1
    }
   ],
   "metadata": {}
  }
 ]
}