Cover......Page 1
Preface......Page 6
Contents......Page 8
1.1 Principles of Design......Page 20
1.2 Types of Electrical Machines......Page 22
1.3 Limitations in Design......Page 23
1.5 Outline of the Text......Page 24
2.1 Introduction......Page 26
2.2 Effect of Fringing of Flux......Page 28
2.3 Types of Damper Windings......Page 30
2.4.1 Slot Leakage Flux......Page 32
2.4.4 End Winding or Overhang Leakage Flux......Page 33
2.5.1 Slot Leakage Reactance for Parallel Sided Slots with Single Layer Winding......Page 34
2.5.3 Slot Leakage Reactance for Tapered Slot......Page 38
2.6 Calculation of Pole Leakage Flux(Οel)......Page 39
2.7 Different Types of Stator and Rotor Slots......Page 43
Unsolved Questions......Page 45
3.1 Introduction......Page 48
3.2.1 Diamagnetic Materials......Page 49
3.2.4 Materials for Solid Core......Page 50
3.2.5 Sheet Steels......Page 51
3.3.1 Good Conducting Materials......Page 53
3.3.3 Materials Used for Solders......Page 56
3.3.5 Carbon Materials......Page 57
3.3.6 Superconducting Materials......Page 58
3.4 Insulating Materials......Page 59
3.4.1 Gases as Insulating Materials......Page 60
3.4.3 Liquid Insulating Materials......Page 61
3.4.4 Solid Insulating Materials......Page 62
3.4.5 Different Insulating Materials Available......Page 64
3.4.6 Insulating Materials Used in Electrical Machines......Page 65
3.4.9 Protection of Insulation from Moisture......Page 66
Questions With Short Answers......Page 67
Unsolved Questions......Page 70
4.1 Introduction......Page 72
4.3.1 Heat Dissipation by Radiation......Page 73
4.3.2 Heat Dissipation by Conduction......Page 74
4.3.3 Heat Dissipation by Convection......Page 75
4.4.1 Volume of Air......Page 77
4.5.1 Machine Under Heating......Page 78
4.5.2 Machine Under Cooling......Page 81
4.6.3 Drip, Splash and Hose Proof Type Machines......Page 82
4.6.5 Totally Enclosed, Special Enclosure Type Machines......Page 83
4.7.1 Induced and Force Ventilation......Page 84
4.7.2 Radial Ventilating System......Page 85
4.7.4 Radial and Axial Ventilation in One Machine......Page 86
4.7.6 Cooling of Totally Enclosed Machines......Page 87
4.7.7 Cooling of Turbo-alternators......Page 89
4.7.8 Direct Cooling (of Turbo-alternator)......Page 91
4.8.2 Standard Ratings of Electrical Machines......Page 93
4.8.3 Different Rating (Duty) of Machine......Page 94
4.8.5 Selection of Motor Capacity for Different Ratings......Page 95
4.9.3 Embedded Temperature Detector Method (ETD)......Page 97
Solved Problems......Page 98
Questions With Short Answers......Page 101
Unsolved Problems......Page 107
5.2 Construction of Alternator......Page 109
5.2.1 Stator Construction......Page 111
5.2.2 Rotor Construction......Page 112
5.4 E.M.F. Equation of an Alternator......Page 116
5.5.1 Distribution Factor......Page 117
5.5.2 Pitch Factor......Page 118
5.6 Flux Density Distribution Curve: Salient Pole Machine......Page 119
5.7.1 Specific Electric Loading......Page 121
5.7.2 Magnetic Loading: Specific Magnetic Loading B or BΞ΄1......Page 122
5.8.1 Output Equation......Page 123
5.8.2 Derivation of Output Equation......Page 124
5.9.1 Salient Pole Alternator (Water Wheel Generator)......Page 125
5.9.2 Steps for Estimation of D and L of Salient Pole Alternator......Page 127
5.10 Runaway Speed......Page 129
5.11 Effective Length of Alternator (Le)......Page 130
5.13 Selection of Stator Slots......Page 131
5.14 Estimation of Turns Per Phase, Total Conductors, Conductors Per Slot and Their Corrected Values......Page 132
5.15 Design of Teeth and Slots......Page 135
5.15.1 Estimation of Size of Teeth and Slots......Page 136
5.17 Sectional Area of Stator Conductor and Slot Insulation......Page 137
5.18 Stator Yoke Design......Page 139
5.19 Stator Copper and Iron Losses, Weight of Iron and Copper......Page 141
5.20 Design of Damper Windings......Page 144
5.21 Rotor Design of Salient Pole Synchronous Alternator......Page 148
5.21.1 Pole Profile Drawing of Salient Pole Alternator......Page 149
5.21.2 Height of Pole Yoke......Page 151
5.21.3 Height of the Pole Core of Salient Pole Machine......Page 152
5.22.1 MMF for Air Gap......Page 153
5.22.2 Pole Leakage Flux......Page 157
5.23.1 Slot Leakage Reactance......Page 159
5.23.2 Tooth Top Leakage Reactance......Page 160
5.24 Determination of Full Load Field MMF......Page 161
5.26 Design of Field Winding of Salient Pole Alternator......Page 163
5.27 Field Losses, Total Loss, Efficiency and Regulation......Page 165
5.28.1 Temperature Rise of Field Coils......Page 166
5.28.2 Temperature Rise of Stator......Page 167
5.29 Rotor Design for Turbo-Alternator......Page 169
Solved Problems on Alternator......Page 172
Problems with Short Answers......Page 204
Unsolved Problems......Page 206
6.1 Introduction......Page 209
6.2.2 Rotor......Page 210
6.2.6 Shafts and Bearings......Page 212
6.3 Output Equation......Page 213
6.5 Estimation of Main Dimensions......Page 214
6.6 Effective Length of Machine (Le)......Page 215
6.7 Estimation of Turns Per Phase (Nph), Total Conductors (Zr) and Conductors Per Slot (Nc) etc. and Their Corrected Values......Page 216
6.9 Cross-Sectional Area of Conductor......Page 218
6.10 Stator Slot Design......Page 219
6.11 Tooth Design......Page 220
6.13 Outer Diameter......Page 221
6.14 Stator Winding Resistance, Copper Loss, Iron Loss, Stator Weight etc.......Page 222
6.15.2 Number of Rotor Slots......Page 223
6.15.4 Rotor Current......Page 224
6.15.5 Sectional Area of Rotor Conductor......Page 225
6.15.6 Rotor Slot Design......Page 226
6.15.9 Rotor Copper Loss......Page 227
6.16 Efficiency......Page 228
6.17 Concept of Flattened Flux Density (B30 or B60)......Page 229
6.18.1 Magnetizing Current (lu)......Page 230
6.18.2 Estimation of Loss Component of the Current (Ic)......Page 232
6.19.1 Estimation of Leakage Reactance......Page 234
6.19.2 Calculation of Resistance......Page 237
6.20 Construction of Circle Diagram From Design Data......Page 238
6.21 Stator Temperature Rise......Page 240
Solved Problems on Three-Phase Induction Motors and Overall Design of Induction Motor......Page 241
Questions With Short Answers......Page 261
Unsolved Questions......Page 263
7.1 Introduction......Page 265
7.3.1 Field System......Page 266
7.3.2 Armature......Page 270
7.3.4 Brushes......Page 272
7.4.2 Factors Affecting the Choice of Specific Electric Loading (ac)......Page 273
7.4.4 Effect of Armature Reaction......Page 274
7.4.5 Armature Winding Terms......Page 275
7.4.7 Types of Armature Winding......Page 276
7.5 Output Equation......Page 278
7.6 Determination of Pa for Different Machines......Page 280
7.7.2 Selection of Specific Electric Loading (ac)......Page 281
7.8.2 Weight of Iron Parts......Page 282
7.8.4 Commutator Length......Page 284
7.8.6 Flash Over......Page 285
7.9.1 Factors for Selection of Core Length......Page 286
7.10 Estimation of Main Dimension (D & L)- (Separation of D and L)......Page 287
7.12 Calculation of Air Gap Length......Page 289
7.13.1 Armature Winding......Page 290
7.13.3 Number of Commutator Segments......Page 291
7.13.4 Factors Effecting the Choice of Number of Slots......Page 292
7.13.7 Selection of Current Density......Page 293
7.13.10 Dimensions of the Slot......Page 294
7.13.11 Resistance of Armature and Armature Voltage Drop......Page 295
7.13.13 Height of Armature Core......Page 296
7.15.1 Sectional Area of Pole......Page 298
7.15.2 Design of Height of Pole......Page 299
7.15.3 Yoke Design......Page 302
7.17 MMF of the Magnetic Circuit and OCC......Page 303
7.18 Design of Shunt Field Winding......Page 305
7.19 Design of Commutator......Page 307
7.20.2 Design of Interpoles......Page 309
7.22 Losses and Efficiency......Page 312
Solved Problems......Page 314
Problems with Short Answers......Page 349
Unsolved Questions......Page 351
8.2 Types of Transformers......Page 352
8.2.1 Core Type Transformers......Page 353
8.3.1 Distribution Transformers......Page 354
8.4 Core and Yoke......Page 355
8.5 Stepped Core and Yoke......Page 356
8.7 Tank and Accessories like Conservator, Breather, Bushings......Page 357
8.8 Output Equation......Page 358
8.8.1 Single-phase (1-Ο) Core Type......Page 360
8.8.2 Output Equation of Single-phase (1-Ο) Shell Type......Page 361
8.8.3 Output Equation for a 3-phase (3-Ο)Core Type Transformer......Page 362
8.8.4 Output Equation of a 3-phase (3-Ο) Shell Type Transformer......Page 363
8.9 Window Space Factor, Current Density and Flux Density......Page 364
8.10 EMF Per Turn (Et)......Page 365
8.11 Different Dimensions of Transformer......Page 367
8.12 Steps to Design a Transformer......Page 370
8.13 Estimation of NO Load Current: (lo)......Page 371
8.14 Determination of Number of Turns and Length of Mean Turns of Windings......Page 373
8.15 Resistance of H.V. Winding and L.V. Winding......Page 375
8.16 Leakage Reactance......Page 376
8.17 Regulation......Page 382
8.18 Estimation of Losses and Efficiency of a Transformer......Page 383
8.19 Design of Tank......Page 384
8.19.1 Main Dimensions of Tank......Page 386
Solved Problems on Transformers......Page 388
Questions with Short Answers......Page 400
Unsolved Problems......Page 403
9.1 Introduction......Page 408
9.2.1 Advantages of Computer Aided Design......Page 409
9.3.2 Synthesis Method of Design......Page 410
9.3.3 Hybrid Method of Design......Page 412
9.5 Standardisation of Design......Page 413
10.2 Computer Aided Design of 3-Phase Alternator......Page 414
10.3 Computer Aided Design of 3-Phase Induction Motor......Page 426
10.3.1 Flow Chart for Overall Design of 3-phase Induction Motor......Page 432
10.4 Computer Aided Design of D.C. Machines......Page 433
10.5.1 Flow Chart for Overall Design of Transformers......Page 439
MATLAB Program of Design Problem, Answer and Discussion......Page 440
Appendix A: Tables for Standard Sizes and Insulation Covering......Page 449
Appendix B: Standard Specifications......Page 457
Bibliography......Page 458