Electric Machines and Drives: A First Course

ISBN-13: 9781118074817 / Angielski / Twarda / 2012 / 288 str.

Ned Mohan

Opis

Mohan's Electric Machines and Drives is part of a three-book series designed for the power sequence electives on Electrical Engineering. The book focuses on power topics including advances in hybrid-electric cars and alternative energy systems, coupled with severe environmental problems associated with hydrocarbon-based fuels. The text builds off Mohan's successful MNPERE titles and adopts a systems approach.

Spis treści

PREFACE xi

CHAPTER 1 INTRODUCTION TO ELECTRIC DRIVE SYSTEMS 1

1.1 History 1

1.2 What Is an Electric–Motor Drive? 2

1.3 Factors Responsible for the Growth of Electric Drives 3

1.4 Typical Applications of Electric Drives 3

1.5 The Multi–Disciplinary Nature of Drive Systems 8

1.6 Structure of the Textbook 9

References 10

Problems 11

CHAPTER 2 UNDERSTANDING MECHANICAL SYSTEM REQUIREMENTS FOR ELECTRIC DRIVES 12

2.1 Introduction 12

2.2 Systems with Linear Motion 12

2.3 Rotating Systems 14

2.4 Friction 20

2.5 Torsional Resonances 21

2.6 Electrical Analogy 22

2.7 Coupling Mechanisms 23

2.8 Types of Loads 26

2.9 Four–Quadrant Operation 27

2.10 Steady State and Dynamic Operations 27

References 28

Problems 28

CHAPTER 3 REVIEW OF BASIC ELECTRIC CIRCUITS 31

3.1 Introduction 31

3.2 Phasor Representation in Sinusoidal Steady State 31

3.3 Three–Phase Circuits 38

Reference 43

Problems 43

CHAPTER 4 BASIC UNDERSTANDING OF SWITCH–MODE POWER ELECTRONIC CONVERTERS IN ELECTRIC DRIVES 46

4.1 Introduction 46

4.2 Overview of Power Processing Units (PPUs) 46

4.3 Converters for DC Motor Drives ð2Vd , vo , VdÞ 52

4.4 Synthesis of Low–Frequency AC 58

4.5 Three–Phase Inverters 59

4.6 Power Semiconductor Devices 62

References 66

Problems 66

CHAPTER 5 MAGNETIC CIRCUITS 69

5.1 Introduction 69

5.2 Magnetic Field Produced by Current–Carrying Conductors 69

5.3 Flux Density B and the Flux f 71

5.4 Magnetic Structures with Air Gaps 74

5.5 Inductances 76

5.6 Faraday s Law: Induced Voltage in a Coil due to Time–Rate of Change of Flux Linkage 78

5.7 Leakage and Magnetizing Inductances 81

5.8 Transformers 83

5.9 Permanent Magnets 88

References 90

Problems 90

CHAPTER 6 BASIC PRINCIPLES OF ELECTROMECHANICAL ENERGY CONVERSION 92

6.1 Introduction 92

6.2 Basic Structure 92

6.3 Production of Magnetic Field 94

6.4 Basic Principles of Operation 96

6.5 Application of the Basic Principles 98

6.6 Energy Conversion 99

6.7 Power Losses and Energy Efficiency 101

6.8 Machine Ratings 102

References 103

Problems 103

CHAPTER 7 DC–MOTOR DRIVES AND ELECTRONICALLYCOMMUTATED MOTOR (ECM) DRIVES 108

7.1 Introduction 108

7.2 The Structure of DC Machines 109

7.3 Operating Principles of DC Machines 111

7.4 DC–Machine Equivalent Circuit 117

7.5 Various Operating Modes in DC–Motor Drives 119

7.6 Flux Weakening in Wound–Field Machines 122

7.7 Power–Processing Units in DC Drives 123

7.8 Electronically–Commutated Motor (ECM) Drives 123

References 129

Problems 129

CHAPTER 8 DESIGNING FEEDBACK CONTROLLERS FOR MOTOR DRIVES 132

8.1 Introduction 132

8.2 Control Objectives 132

8.3 Cascade Control Structure 135

8.4 Steps in Designing the Feedback Controller 135

8.5 System Representation for Small–Signal Analysis 136

8.6 Controller Design 138

8.7 Example of a Controller Design 139

8.8 The Role of Feed–Forward 145

8.9 Effects of Limits 145

8.10 Anti–Windup (Non–Windup) Integration 146

References 147

Problems and Simulations 147

CHAPTER 9 INTRODUCTION TO AC MACHINES AND SPACE VECTORS 149

9.1 Introduction 149

9.2 Sinusoidally–Distributed Stator Windings 149

9.3 The Use of Space Vectors to Represent Sinusoidal Field Distributions in the Air Gap 156

9.4 Space–Vector Representation of Combined Terminal Currents and Voltages 159

9.5 Balanced Sinusoidal Steady–State Excitation (Rotor Open–Circuited) 164

References 172

Problems 172

CHAPTER 10 SINUSOIDAL PERMANENT MAGNET AC (PMAC) DRIVES, LCI–SYNCHRONOUS MOTOR DRIVES, AND SYNCHRONOUS GENERATORS 174

10.1 Introduction 174

10.2 The Basic Structure of Permanent–Magnet AC (PMAC) Machines 175

10.3 Principle of Operation 175

10.4 The Controller and the Power–Processing Unit (PPU) 185

10.5 Load–Commutated–Inverter (LCI) Supplied Synchronous Motor Drives 186

10.6 Synchronous Generators 187

References 191

Problems 191

CHAPTER 11 INDUCTION MOTORS: BALANCED, SINUSOIDAL STEADY STATE OPERATION 193

11.1 Introduction 193

11.2 The Structure of Three–Phase, Squirrel–Cage Induction Motors 194

11.3 The Principles of Induction Motor Operation 194

11.4 Tests to Obtain the Parameters of the Per–Phase Equivalent Circuit 215

11.5 Induction Motor Characteristics at Rated Voltages in Magnitude and Frequency 216

11.6 Induction Motors of Nema Design A, B, C, and D 218

11.7 Line Start 219

11.8 Reduced Voltage Starting ( soft start ) of Induction Motors 220

11.9 Energy–Savings in Lightly–Loaded Machines 220

11.10 Doubly–Fed Induction Generators (DFIG) in Wind Turbines 221

References 228

Problems 229

CHAPTER 12 INDUCTION–MOTOR DRIVES: SPEED CONTROL 231

12.1 Introduction 231

12.2 Conditions for Efficient Speed Control Over a Wide Range 232

12.3 Applied Voltage Amplitudes to Keep ^ Bms 5 ^ Bms;rated 235

12.4 Starting Considerations in Drives 239

12.5 Capability to Operate below and above the Rated Speed 240

12.6 Induction–Generator Drives 242

12.7 Speed Control of Induction–Motor Drives 243

12.8 Pulse–Width–Modulated Power–Processing Unit 244

12.9 Reduction of ^ Bms at Light Loads 248

References 249

Problems 249

CHAPTER 13 RELUCTANCE DRIVES: STEPPER–MOTOR AND SWITCHED–RELUCTANCE DRIVES 250

13.1 Introduction 250

13.2 The Operating Principle of Reluctance Motors 251

13.3 Stepper–Motor Drives 253

13.4 Switched–Reluctance Motor Drives 259

References 260

Problems 260

CHAPTER 14 ENERGY EFFICIENCY OF ELECTRIC DRIVES AND INVERTER–MOTOR INTERACTIONS 261

14.1 Introduction 261

14.2 The Definition of Energy Efficiency in Electric Drives 261

14.3 The Energy Efficiency of Induction Motors with Sinusoidal Excitation 262

14.4 The Effects of Switching–Frequency Harmonics on Motor Losses 265

14.5 The Energy Efficiencies of Power–Processing Units 266

14.6 Energy Efficiencies of Electric Drives 266

14.7 The Economics of Energy Savings by Premium–Efficiency Electric Motors and Electric Drives 266

14.8 The Deleterious Effects of The PWM–Inverter Voltage Waveform on Motor Life 267

14.9 Benefits of Using Variable–Speed Drives 268

References 268

Problem 269

O autorze

Ned Mohan is the Oscar A. Schott Professor of Power Electronics at the University of Minnesota. He has numerous patents and publications in this field. He is a Fellow of the IEEE.

Blurb

WILEY INTRODUCES A NEW SERIES ON POWER SYSTEMS FOR THE NEXT GENERATION OF SUSTAINABLE POWER.

By Ned Mohan, University of Minnesota

Working with a number of universities, Dr. Ned Mohan has developed a forward–looking curriculum for teaching undergraduate courses in Power Systems, Power Electronics and Electric Machines and Drives. This groundbreaking new series is based on that curriculum and represent the next generation in the engineering of sustainable power. Dr. Mohan has been a leader in Electric Energy systems education and research for decades, as an author of the best–selling text/reference Power Electronics published by Wiley.

HALLMARK FEATURES OF THE SERIES

• Brief, accessible coverage designed for undergraduates and readers new to power systems engineering.
• Updated with modern application examples related to renewable energy and the ′smart grid.′
• Supplemented with a wide range of digital resources slides, video clips, animations, and lab manuals. (For instructors)
• Builds off the author′s publications in the area.
• Adopts a systems approach, which puts otherwise dry technical detail in the context of applications that motivate students and readers (hybrid cars, wind turbines, etc.)
• Briefer and more suitable for an undergraduate audience or engineers new to this area than competing titles.

ELECTRIC MACHINES AND DRIVES: A FIRST COURSE

This book focuses on Electric Machines and Drives as one of the topics in an integrated Electric Energy Systems curriculum. It follows a top–down, systems–level approach to highlight interrelationships between the sub–fields within this curriculum, and is intended to cover both the fundamentals and practical design in a single–semester course.