Principles of Electric Machines with Power Electronic Applications

PREFACE ix

Chapter 1 INTRODUCTION 1

1.1 Electric Machines 1

1.2 Roots in Observation 2

1.3 Beginnings 3

1.4 Foundations of Electromagnetism 5

1.5 The Dawn of Electrodynamics 7

1.6 Early Electric Generators 9

1.7 Early Electric Motors 10

1.8 Alternating Current 11

1.9 Power Electronics: Scope and A Brief History 13

1.10 Structure of the Power System 18

1.11 Outline of the Text 21

Chapter 2 PRINCIPLES OF ELECTROMAGNETISM AND ELECTROMECHANICAL ENERGY CONVERSION 23

2.1 Introduction 23

2.2 Magnetic-Field Laws 24

2.3 Permeability and Magnetic-Field Intensity 31

2.4 Magnetic Circuits 35

2.5 Flux Linkages, Induced Voltages, Inductance, and Energy 50

2.6 Hysteresis Loop 54

2.7 Eddy-Current and Core Losses 59

2.8 Energy Flow Approach 60

2.9 Field Energy 64

2.10 Multiply Excited Systems 69

2.11 Reluctance Motors 72

2.12 Doubly Excited Systems 75

2.13 Salient-Pole Machines 77

2.14 Round or Smooth Air-Gap Machines 80

2.15 Machine-Type Classification 84

2.16 P-Pole Machines 85

Problems 89

Chapter 3 POWER ELECTRONIC DEVICES AND SYSTEMS 103

3.1 Introduction 103

3.2 Power Semiconductor Devices 103

3.3 Control Characteristics of Power Devices 106

3.4 Power Semiconductor Diodes 108

3.5 Power Transistors 115

3.6 The Thyristors 138

3.7 Power Electronic Systems 175

3.8 Power Integrated Circuits and Smart Power 178

Problems 179

Chapter 4 DIRECT-CURRENT MOTORS 183

4.1 Introduction 183

4.2 Construction Features 184

4.3 Circuit Model of dc Generator 185

4.4 Circuit Model of dc Motors 187

4.5 dc Series Motors 190

4.6 dc Shunt Motors 203

4.7 Compound Motors 212

4.8 Motor and Load Matching 224

4.9 Conventional Speed Control of dc Motors 224

4.10 Reversal of Direction of Rotation 241

4.11 Starting dc Motors 241

4.12 Adjustable Speed dc Motor Drives 251

4.13 ac-dc Drives for dc Motors 255

4.14 dc-dc Drives for dc Motors 261

Problems 265

Chapter 5 TRANSFORMERS 273

5.1 Introduction 273

5.2 Ideal Transformers 274

5.3 Transformer Models 278

5.4 Transformer Performance Measures 286

5.5 Single-Phase Connections 292

5.6 Three-Winding Transformers 296

5.7 Three-Phase Systems and Transformer Connections 300

5.8 Autotransformers 313

Problems 316

Chapter 6 INDUCTION MOTORS AND THEIR CONTROL 323

6.1 Introduction 323

6.2 MMF Waves and the Rotating Magnetic Field 324

6.3 Slip 329

6.4 Equivalent Circuits 331

6.5 Simplified Equivalent Circuits 334

6.6 Torque Characteristics 338

6.7 Some Useful Relations 341

6.8 Internal Mechanical Power 344

6.9 Effects of Rotor Impedance 348

6.10 Classification of Induction Motors 351

6.11 Starting Induction Motors 354

6.12 Conventional Speed Control of Induction Motors 362

6.13 Adjustable Speed Drives: General Considerations 370

6.14 Variable-Voltage-Constant-Frequency Drives 372

6.15 Variable-Voltage-Variable-Frequency Drives 376

6.16 dc-Link-Converter Drives 381

6.17 Voltage-Fed Inverter Drives 383

6.18 Current-Fed Inverter Drives 385

6.19 Cycloconverter Drives 386

6.20 Regulation of Slip Power 387

Problems 389

Chapter 7 SYNCHRONOUS MACHINES 397

7.1 Introduction 397

7.2 Round-Rotor Machines: Equivalent Circuit 401

7.3 Armature Reaction 406

7.4 Principal Steady-State Characteristics 410

7.5 Power Angle Characteristics and the Infinite-Bus Concept 415

7.6 Synchronous-Motor Operation 423

7.7 Salient-Pole Machines 430

Problems 437

Chapter 8 FRACTIONAL-HORSEPOWER ALTERNATING CURRENT MOTORS 443

8.1 Introduction 443

8.2 Rotating Magnetic Fields in Single-Phase Induction Motors 443

8.3 Equivalent Circuits for Single-Phase Induction Motors 448

8.4 Power and Torque Relations 454

8.5 Starting Single-Phase Induction Motors 459

Problems 473

BIBLIOGRAPHY 475

INDEX 477