WIND ENERGY SYSTEMS - Cd3wd

More documents

Recommendations

Info

Chapter 5—Electrical Network 5–58 9 PROBLEMS 1. In the circuit of Fig. 30, the applied single-phase voltage is 250 V and the frequency is 60 Hz. The magnitude of the current in the series RL branch is |I 2 | =10A. (a) What is the real power supplied to the circuit? (b) What is the net reactive power supplied to the circuit? Is it positive or negative? (c) What is the power factor of the circuit and is it leading or lagging? Figure 30: Circuit diagram for Problem 1. 2. In the circuit of Fig. 31, a total real power of 4000 W is being supplied to the single-phase circuit. The input current magnitude is |I 1 | =8A. (a) Find |I 2 |. (b) Find |V 2 |. (c) Assume that V 2 = |V 2 |/0 o and draw V 2 , I 2 , I c ,andI 1 on a phasor diagram. (d) Determine X C . Figure 31: Circuit diagram for Problem 2. 3. A load connected across a single-phase 240-V, 60-Hz source draws 10 kW at a lagging power factor of 0.5. Determine the current and the reactive power. Wind Energy Systems by Dr. Gary L. Johnson November 21, 2001
Chapter 5—Electrical Network 5–59 4. A small industry has a number of induction motors which require a total apparent power of 100 kVA at a lagging power factor of 0.6. It also has 20 kW of resistance heating. What is the total apparent power required by the industry and what is the overall power factor? 5. A single-phase generator supplies a voltage E to the input of a transmission line represented by a series impedance Z t =1+j3 Ω. The load voltage V is 250 /0 o V. The circuit is shown in Fig. 32. (a) With switch S 1 open, calculate the current I 1 , and the real power, reactive power, and power factor of the load. (b) Calculate the generator voltage E. (c) Calculate the power lost in the transmission line. (d) With switch S 1 closed and the voltage V remaining at 250/0 o , find the capacitor current I c , the new input current I 1 , and the new overall power factor. (e) Calculate the new generator voltage and the new transmission line power loss. (f) List two advantages of adding a capacitor to an inductive load. Figure 32: Circuit diagram for Problem 5. 6. A three-phase load draws 250 kW at a power factor of 0.707 lagging from a 440-V line. In parallel with this load is a three-phase capacitor bank which draws 60 kVA. Find the magnitude of the line current and the overall power factor. 7. A wind turbine of the same rating as the MOD-1 has a synchronous generator rated at 2000 kW (2500 kVA at 0.8 power factor) at 4160 V line to line. The machine impedance is 0.11 + j10Ω/phase. The generator is delivering 1500 kW to a load at 0.9 power factor lagging. Find the phasor current, the phasor generated voltage E, the power angle δ, the total pullout power, and the ohmic losses in the generator stator. 8. The field supply for the machine in the previous problem loses a diode. This causes |E| to decrease by 10 percent. Real power being delivered to the utility grid is determined by the wind power input and does not change. What is the new power angle δ and the new total reactive power being supplied to the utility grid? Wind Energy Systems by Dr. Gary L. Johnson November 21, 2001
Page 1 and 2:
WIND ENERGY SYSTEMS Electronic Edit
Page 3 and 4:
ii 4 Wind Turbine Power, Energy, an
Page 5 and 6:
iv 9.9 Wind farm Costs.............
Page 7 and 8:
vi and Chapter 8, so we can give a
Page 9 and 10:
Chapter 1—Introduction 1-1 INTROD
Page 11 and 12:
Chapter 1—Introduction 1-3 same w
Page 13 and 14:
Chapter 1—Introduction 1-5 Thomas
Page 15 and 16:
Chapter 1—Introduction 1-7 Figure
Page 17 and 18:
Chapter 1—Introduction 1-9 power
Page 19 and 20:
Chapter 1—Introduction 1-11 servi
Page 21 and 22:
Chapter 1—Introduction 1-13 incre
Page 23 and 24:
Chapter 1—Introduction 1-15 Figur
Page 25 and 26:
Chapter 1—Introduction 1-17 three
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
Chapter 1—Introduction 1-23 [9] R
Page 33 and 34:
Chapter 2—Wind Characteristics 2-
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
Page 41 and 42:
Page 43 and 44:
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Page 55 and 56:
Page 57 and 58:
Page 59 and 60:
Page 61 and 62:
Page 63 and 64:
Page 65 and 66:
Page 67 and 68:
Page 69 and 70:
Page 71 and 72:
Page 73 and 74:
Page 75 and 76:
Page 77 and 78:
Page 79 and 80:
Page 81 and 82:
Page 83 and 84:
Page 85 and 86:
Page 87 and 88:
Page 89 and 90:
Page 91 and 92:
Page 93 and 94:
Page 95 and 96:
Page 97 and 98:
Page 99 and 100:
Page 101 and 102:
Chapter 3—Wind Measurements 3-2 g
Page 103 and 104:
Chapter 3—Wind Measurements 3-4 F
Page 105 and 106:
Chapter 3—Wind Measurements 3-6 i
Page 107 and 108:
Chapter 3—Wind Measurements 3-8 F
Page 109 and 110:
Chapter 3—Wind Measurements 3-10
Page 111 and 112:
Page 113 and 114:
Page 115 and 116:
Page 117 and 118:
Page 119 and 120:
Page 121 and 122:
Page 123 and 124:
Page 125 and 126:
Page 127 and 128:
Page 129 and 130:
Page 131 and 132:
Page 133 and 134:
Page 135 and 136:
Page 137 and 138:
Chapter 4—Wind Turbine Power 4-1
Page 139 and 140:
Page 141 and 142:
Page 143 and 144:
Page 145 and 146:
Page 147 and 148:
Page 149 and 150:
Page 151 and 152:
Page 153 and 154:
Page 155 and 156:
Page 157 and 158:
Page 159 and 160:
Page 161 and 162:
Page 163 and 164:
Page 165 and 166:
Page 167 and 168:
Page 169 and 170:
Page 171 and 172:
Page 173 and 174:
Page 175 and 176:
Page 177 and 178:
Page 179 and 180:
Page 181 and 182:
Page 183 and 184:
Page 185 and 186:
Page 187 and 188:
Page 189 and 190:
Page 191 and 192:
Chapter 5—Electrical Network 5-1
Page 193 and 194:
Page 195 and 196:
Page 197 and 198: Chapter 5—Electrical Network 5-7
Page 247: Chapter 5—Electrical Network 5-57
Page 253 and 254: Chapter 6—Asynchronous Generators
Page 297 and 298: Chapter 7—Asynchronous Loads 7-2
Page 299 and 300:
Chapter 7—Asynchronous Loads 7-4
Page 301 and 302:
Page 303 and 304:
Page 305 and 306:
Page 307 and 308:
Page 309 and 310:
Page 311 and 312:
Page 313 and 314:
Page 315 and 316:
Page 317 and 318:
Page 319 and 320:
Page 321 and 322:
Page 323 and 324:
Page 325 and 326:
Page 327 and 328:
Page 329 and 330:
Page 331 and 332:
Page 333 and 334:
Page 335 and 336:
Page 337 and 338:
Page 339 and 340:
Page 341 and 342:
Page 343 and 344:
Page 345 and 346:
Page 347 and 348:
Chapter 8—Economics 8-2 are the t
Page 349 and 350:
Chapter 8—Economics 8-4 Table 8.1
Page 351 and 352:
Chapter 8—Economics 8-6 by the di
Page 353 and 354:
Chapter 8—Economics 8-8 understan
Page 355 and 356:
Chapter 8—Economics 8-10 bank at
Page 357 and 358:
Chapter 8—Economics 8-12 i a = 1+
Page 359 and 360:
Chapter 8—Economics 8-14 ( ) 20 1
Page 361 and 362:
Chapter 8—Economics 8-16 and the
Page 363 and 364:
Chapter 8—Economics 8-18 The unit
Page 365 and 366:
Chapter 8—Economics 8-20 L ′ fu
Page 367 and 368:
Chapter 8—Economics 8-22 L ′ vo
Page 369 and 370:
Chapter 8—Economics 8-24 conventi
Page 371 and 372:
Chapter 8—Economics 8-26 7 PROBLE
Page 373 and 374:
Chapter 8—Economics 8-28 [2] Boll
Page 375 and 376:
Chapter 9—Wind Power Plants 9-2 6
Page 377 and 378:
Chapter 9—Wind Power Plants 9-4 w
Page 379 and 380:
Chapter 9—Wind Power Plants 9-6 t
Page 381 and 382:
Chapter 9—Wind Power Plants 9-8 s
Page 383 and 384:
Chapter 9—Wind Power Plants 9-10
Page 385 and 386:
Page 387 and 388:
Page 389 and 390:
Page 391 and 392:
Page 393 and 394:
Page 395 and 396:
Page 397 and 398:
Page 399 and 400:
Page 401 and 402:
Page 403 and 404:
Page 405 and 406:
Page 407 and 408:
Page 409 and 410:
Page 411 and 412:
Page 413 and 414:
Page 415 and 416:
Page 417 and 418:
Page 419:
show all

WIND ENERGY SYSTEMS - Cd3wd

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?