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Control of Electric Machine Drive Systems

Seung-Ki Sul

ISBN: 978-0-470-59079-9 January 2011 Wiley-IEEE Press 424 Pages


A unique approach to sensorless control and regulator design of electric drives

Based on the author's vast industry experience and collaborative works with other industries, Control of Electric Machine Drive Systems is packed with tested, implemented, and verified ideas that engineers can apply to everyday problems in the field. Originally published in Korean as a textbook, this highly practical updated version features the latest information on the control of electric machines and apparatus, as well as a new chapter on sensorless control of AC machines, a topic not covered in any other publication.

The book begins by explaining the features of the electric drive system and trends of development in related technologies, as well as the basic structure and operation principles of the electric machine. It also addresses steady state characteristics and control of the machines and the transformation of physical variables of AC machines using reference frame theory in order to provide a proper foundation for the material.

The heart of the book reviews several control algorithms of electric machines and power converters, explaining active damping and how to regulate current, speed, and position in a feedback manner. Seung-Ki Sul introduces tricks to enhance the control performance of the electric machines, and the algorithm to detect the phase angle of an AC source and to control DC link voltages of power converters. Topics also covered are:

  • Vector control
  • Control algorithms for position/speed sensorless drive of AC machines
  • Methods for identifying the parameters of electric machines and power converters
  • The matrix algebra to model a three-phase AC machine in d-q-n axes

Every chapter features exercise problems drawn from actual industry experience. The book also includes more than 300 figures and offers access to an FTP site, which provides MATLAB programs for selected problems. The book's practicality and realworld relatability make it an invaluable resource for professionals and engineers involved in the research and development of electric machine drive business, industrial drive designers, and senior undergraduate and graduate students.

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To visit this book's FTP site to download MATLAB codes, please click on this link: 

MATLAB codes are also downloadable from Wiley Booksupport Site at


Preface xiii

1 Introduction 1

1.1 Introduction 1

1.1.1 Electric Machine Drive System 4

1.1.2 Trend of Development of Electric Machine Drive System 5

1.1.3 Trend of Development of Power Semiconductor 7

1.1.4 Trend of Development of Control Electronics 8

1.2 Basics of Mechanics 8

1.2.1 Basic Laws 9

1.2.2 Force and Torque 9

1.2.3 Moment of Inertia of a Rotating Body 11

1.2.4 Equations of Motion for a Rigid Body 13

1.2.5 Power and Energy 17

1.2.6 Continuity of Physical Variables 18

1.3 Torque Speed Curve of Typical Mechanical Loads 18

1.3.1 Fan, Pump, and Blower 18

1.3.2 Hoisting Load; Crane, Elevator 20

1.3.3 Traction Load (Electric Vehicle, Electric Train) 21

1.3.4 Tension Control Load 23

Problems 24

References 35

2 Basic Structure and Modeling of Electric Machines and Power Converters 36

2.1 Structure and Modeling of DC Machine 36

2.2 Analysis of Steady-State Operation 41

2.2.1 Separately Excited Shunt Machine 42

2.2.2 Series Excited DC Machine 45

2.3 Analysis of Transient State of DC Machine 46

2.3.1 Separately Excited Shunt Machine 47

2.4 Power Electronic Circuit to Drive DC Machine 50

2.4.1 Static Ward–Leonard System 51

2.4.2 Four-Quadrants Chopper System 52

2.5 Rotating Magnetic Motive Force 53

2.6 Steady-State Analysis of a Synchronous Machine 58

2.7 Linear Electric Machine 62

2.8 Capability Curve of Synchronous Machine 63

2.8.1 Round Rotor Synchronous Machine with Field Winding 63

2.8.2 Permanent Magnet Synchronous Machine 64

2.9 Parameter Variation of Synchronous Machine 66

2.9.1 Stator and Field Winding Resistance 66

2.9.2 Synchronous Inductance 66

2.9.3 Back EMF Constant 67

2.10 Steady-State Analysis of Induction Machine 70

2.10.1 Steady-State Equivalent Circuit of an Induction Machine 72

2.10.2 Constant Air Gap Flux Operation 77

2.11 Generator Operation of an Induction Machine 79

2.12 Variation of Parameters of an Induction Machine 81

2.12.1 Variation of Rotor Resistance, Rr 81

2.12.2 Variation of Rotor Leakage Inductance, Llr 82

2.12.3 Variation of Stator Resistance, Rs 82

2.12.4 Variation of Stator Leakage Inductance, Lls 83

2.12.5 Variation of Excitation Inductance, Lm 84

2.12.6 Variation of Resistance Representing Iron Loss, Rm 84

2.13 Classification of Induction Machines According to Speed–Torque Characteristics 84

2.14 Quasi-Transient State Analysis 87

2.15 Capability Curve of an Induction Machine 88

2.16 Comparison of AC Machine and DC Machine 90

2.16.1 Comparison of a Squirrel Cage Induction Machine and a Separately Excited DC Machine 90

2.16.2 Comparison of a Permanent Magnet AC Machine and a Separately Excited DC Machine 92

2.17 Variable-Speed Control of Induction Machine Based on Steady-State Characteristics 92

2.17.1 Variable Speed Control of Induction Machine by Controlling Terminal Voltage 93

2.17.2 Variable Speed Control of Induction Machine Based on Constant Air-Gap Flux (͌≈V=F) Control 94

2.17.3 Variable Speed Control of Induction Machine Based on Actual Speed Feedback 95

2.17.4 Enhancement of Constant Air-Gap Flux Control with Feedback of Magnitude of Stator Current 96

2.18 Modeling of Power Converters 96

2.18.1 Three-Phase Diode/Thyristor Rectifier 97

2.18.2 PWM Boost Rectifier 98

2.18.3 Two-Quadrants Bidirectional DC/DC Converter 101

2.18.4 Four-Quadrants DC/DC Converter 102

2.18.5 Three-Phase PWM Inverter 103

2.18.6 Matrix Converter 105

2.19 Parameter Conversion Using Per Unit Method 106

Problems 108

References 114

3 Reference Frame Transformation and Transient State Analysis of Three-Phase AC Machines 116

3.1 Complex Vector 117

3.2 d–q–n Modeling of an Induction Machine Based on Complex Space Vector 119

3.2.1 Equivalent Circuit of an Induction Machine at d–q–n AXIS 120

3.2.2 Torque of the Induction Machine 125

3.3 d–q–n Modeling of a Synchronous Machine Based on Complex Space Vector 128

3.3.1 Equivalent Circuit of a Synchronous Machine at d–q–n AXIS 128

3.3.2 Torque of a Synchronous Machine 138

3.3.3 Equivalent Circuit and Torque of a Permanent Magnet Synchronous Machine 140

3.3.4 Synchronous Reluctance Machine (SynRM) 144

Problems 146

References 153

4 Design of Regulators for Electric Machines and Power Converters 154

4.1 Active Damping 157

4.2 Current Regulator 158

4.2.1 Measurement of Current 158

4.2.2 Current Regulator for Three-Phase-Controlled Rectifier 161

4.2.3 Current Regulator for a DC Machine Driven by a PWM Chopper 166

4.2.4 Anti-Wind-Up 170

4.2.5 AC Current Regulator 173

4.3 Speed Regulator 179

4.3.1 Measurement of Speed/Position of Rotor of an Electric Machine 179

4.3.2 Estimation of Speed with Incremental Encoder 182

4.3.3 Estimation of Speed by a State Observer 189

4.3.4 PI/IP Speed Regulator 198

4.3.5 Enhancement of Speed Control Performance with Acceleration Information 204

4.3.6 Speed Regulator with Anti-Wind-Up Controller 206

4.4 Position Regulator 208

4.4.1 Proportional–Proportional and Integral (P–PI) Regulator 208

4.4.2 Feed-Forwarding of Speed Reference and Acceleration Reference 209

4.5 Detection of Phase Angle of AC Voltage 210

4.5.1 Detection of Phase Angle on Synchronous Reference Frame 210

4.5.2 Detection of Phase Angle Using Positive Sequence Voltage on Synchronous Reference Frame 213

4.6 Voltage Regulator 215

4.6.1 Voltage Regulator for DC Link of PWM Boost Rectifier 215

Problems 218

References 228

5 Vector Control 230

5.1 Instantaneous Torque Control 231

5.1.1 Separately Excited DC Machine 231

5.1.2 Surface-Mounted Permanent Magnet Synchronous Motor (SMPMSM) 233

5.1.3 Interior Permanent Magnet Synchronous Motor (IPMSM) 235

5.2 Vector Control of Induction Machine 236

5.2.1 Direct Vector Control 237

5.2.2 Indirect Vector Control 243

5.3 Rotor Flux Linkage Estimator 245

5.3.1 Voltage Model Based on Stator Voltage Equation of an Induction Machine 245

5.3.2 Current Model Based on Rotor Voltage Equation of an Induction Machine 246

5.3.3 Hybrid Rotor Flux Linkage Estimator 247

5.3.4 Enhanced Hybrid Estimator 248

5.4 Flux Weakening Control 249

5.4.1 Constraints of Voltage and Current to AC Machine 249

5.4.2 Operating Region of Permanent Magnet AC Machine in Current Plane at Rotor Reference Frame 250

5.4.3 Flux Weakening Control of Permanent Magnet Synchronous Machine 257

5.4.4 Flux Weakening Control of Induction Machine 262

5.4.5 Flux Regulator of Induction Machine 267

Problems 269

References 281

6 Position/Speed Sensorless Control of AC Machines 283

6.1 Sensorless Control of Induction Machine 286

6.1.1 Model Reference Adaptive System (MRAS) 286

6.1.2 Adaptive Speed Observer (ASO) 291

6.2 Sensorless Control of Surface-Mounted Permanent Magnet Synchronous Machine (SMPMSM) 297

6.3 Sensorless Control of Interior Permanent Magnet Synchronous Machine (IPMSM) 299

6.4 Sensorless Control Employing High-Frequency Signal Injection 302

6.4.1. Inherently Salient Rotor Machine 304

6.4.2 AC Machine with Nonsalient Rotor 305

Problems 317

References 320

7 Practical Issues 324

7.1 Output Voltage Distortion Due to Dead Time and Its Compensation 324

7.1.1 Compensation of Dead Time Effect 325

7.1.2 Zero Current Clamping (ZCC) 327

7.1.3 Voltage Distortion Due to Stray Capacitance of Semiconductor Switches 327

7.1.4 Prediction of Switching Instant 330

7.2 Measurement of Phase Current 334

7.2.1 Modeling of Time Delay of Current Measurement System 334

7.2.2 Offset and Scale Errors in Current Measurement 337

7.3 Problems Due to Digital Signal Processing of Current Regulation Loop 342

7.3.1 Modeling and Compensation of Current Regulation Error Due to Digital Delay 342

7.3.2 Error in Current Sampling 346

Problems 350

References 353

Appendix A Measurement and Estimation of Parameters of Electric Machinery 354

A.1 Parameter Estimation 354

A.1.1 DC Machine 355

A.1.2 Estimation of Parameters of Induction Machine 357

A.2 Parameter Estimation of Electric Machines Using Regulators of Drive System 361

A.2.1 Feedback Control System 361

A.2.2 Back EMF Constant of DC Machine, K 363

A.2.3 Stator Winding Resistance of Three-Phase AC Machine, Rs 363

A.2.4 Induction Machine Parameters 365

A.2.5 Permanent Magnet Synchronous Machine 370

A.3 Estimation of Mechanical Parameters 374

A.3.1 Estimation Based on Mechanical Equation 374

A.3.2 Estimation Using Integral Process 376

References 380

Appendix B d–q Modeling Using Matrix Equations 381

B.1 Reference Frame and Transformation Matrix 381

B.2 d–q Modeling of Induction Machine Using Transformation Matrix 386

B.3 d–q Modeling of Synchronous Machine Using Transformation Matrix 390

Index 391

IEEE Press Series on Power Engineering 401

"The book's practicality and realworld relatability make it an invaluable resource for professionals and engineers involved in the research and development of electric machine drive business, industrial drive designers, and senior undergraduate and graduate students." (, 7 March 2011)
Errata - Control of Electric Machine Drive Systems