# Predictive Control of Power Converters and Electrical Drives

# Predictive Control of Power Converters and Electrical Drives

ISBN: 978-1-119-94264-1

Apr 2012

336 pages

$111.99

## Description

**Describes the general principles and current research into Model Predictive Control (MPC); the most up-to-date control method for power converters and drives**

The book starts with an introduction to the subject before the first chapter on classical control methods for power converters and drives. This covers classical converter control methods and classical electrical drives control methods. The next chapter on Model predictive control first looks at predictive control methods for power converters and drives and presents the basic principles of MPC. It then looks at MPC for power electronics and drives. The third chapter is on predictive control applied to power converters. It discusses: control of a three-phase inverter; control of a neutral point clamped inverter; control of an active front end rectifier, and; control of a matrix converter. In the middle of the book there is Chapter four - Predictive control applied to motor drives. This section analyses predictive torque control of industrial machines and predictive control of permanent magnet synchronous motors. Design and implementation issues of model predictive control is the subject of the final chapter. The following topics are described in detail: cost function selection; weighting factors design; delay compensation; effect of model errors, and prediction of future references. While there are hundreds of books teaching control of electrical energy using pulse width modulation, this will be the very first book published in this new topic.

- Unique in presenting a completely new theoretic solution to control electric power in a simple way
- Discusses the application of predictive control in motor drives, with several examples and case studies
- Matlab is included on a complementary website so the reader can run their own simulations

**Foreword xi**

**Preface xiii**

**Acknowledgments xv**

**Part One INTRODUCTION**

**1 Introduction 3**

1.1 Applications of Power Converters and Drives 3

1.2 Types of Power Converters 5

*1.2.1 Generic Drive System* 5

*1.2.2 Classification of Power Converters* 5

1.3 Control of Power Converters and Drives 7

*1.3.1 Power Converter Control in the Past* 7

*1.3.2 Power Converter Control Today* 10

*1.3.3 Control Requirements and Challenges* 11

*1.3.4 Digital Control Platforms* 12

1.4 Why Predictive Control is Particularly Suited for Power Electronics 13

1.5 Contents of this Book 15

References 16

**2 Classical Control Methods for Power Converters and Drives 17**

2.1 Classical Current Control Methods 17

*2.1.1 Hysteresis Current Control* 18

*2.1.2 Linear Control with Pulse Width Modulation or Space Vector Modulation* 20

2.2 Classical Electrical Drive Control Methods 24

*2.2.1 Field Oriented Control* 24

*2.2.2 Direct Torque Control* 26

2.3 Summary 30

References 30

**3 Model Predictive Control 31**

3.1 Predictive Control Methods for Power Converters and Drives 31

3.2 Basic Principles of Model Predictive Control 32

3.3 Model Predictive Control for Power Electronics and Drives 34

*3.3.1 Controller Design* 35

*3.3.2 Implementation* 37

*3.3.3 General Control Scheme* 38

3.4 Summary 38

References 38

**Part Two MODEL PREDICTIVE CONTROL APPLIED TO POWER CONVERTERS**

**4 Predictive Control of a Three-Phase Inverter 43**

4.1 Introduction 43

4.2 Predictive Current Control 43

4.3 Cost Function 44

4.4 Converter Model 44

4.5 Load Model 48

4.6 Discrete-Time Model for Prediction 49

4.7 Working Principle 50

4.8 Implementation of the Predictive Control Strategy 50

4.9 Comparison to a Classical Control Scheme 59

4.10 Summary 63

References 63

**5 Predictive Control of a Three-Phase Neutral-Point Clamped Inverter 65**

5.1 Introduction 65

5.2 System Model 66

5.3 Linear Current Control Method with Pulse Width Modulation 70

5.4 Predictive Current Control Method 70

5.5 Implementation 72

*5.5.1 Reduction of the Switching Frequency* 74

*5.5.2 Capacitor Voltage Balance* 77

5.6 Summary 78

References 79

**6 Control of an Active Front-End Rectifier 81**

6.1 Introduction 81

6.2 Rectifier Model 84

*6.2.1 Space Vector Model* 84

*6.2.2 Discrete-Time Model* 85

6.3 Predictive Current Control in an Active Front-End 86

*6.3.1 Cost Function* 86

6.4 Predictive Power Control 89

*6.4.1 Cost Function and Control Scheme* 89

6.5 Predictive Control of an AC–DC–AC Converter 92

*6.5.1 Control of the Inverter Side* 92

*6.5.2 Control of the Rectifier Side* 94

*6.5.3 Control Scheme* 94

6.6 Summary 96

References 97

**7 Control of a Matrix Converter 99**

7.1 Introduction 99

7.2 System Model 99

*7.2.1 Matrix Converter Model* 99

*7.2.2 Working Principle of the Matrix Converter* 101

*7.2.3 Commutation of the Switches* 102

7.3 Classical Control: The Venturini Method 103

7.4 Predictive Current Control of the Matrix Converter 104

*7.4.1 Model of the Matrix Converter for Predictive Control* 104

*7.4.2 Output Current Control* 107

*7.4.3 Output Current Control with Minimization of the Input Reactive Power* 108

*7.4.4 Input Reactive Power Control* 113

7.5 Summary 113

References 114

**Part Three MODEL PREDICTIVE CONTROL APPLIED TO MOTOR DRIVES**

**8 Predictive Control of Induction Machines 117**

8.1 Introduction 117

8.2 Dynamic Model of an Induction Machine 118

8.3 Field Oriented Control of an Induction Machine Fed by a Matrix Converter Using Predictive Current Control 121

*8.3.1 Control Scheme* 121

8.4 Predictive Torque Control of an Induction Machine Fed by a Voltage Source Inverter 123

8.5 Predictive Torque Control of an Induction Machine Fed by a Matrix Converter 128

*8.5.1 Torque and Flux Control* 128

*8.5.2 Torque and Flux Control with Minimization of the Input Reactive Power* 129

8.6 Summary 130

References 131

**9 Predictive Control of Permanent Magnet Synchronous Motors 133**

9.1 Introduction 133

9.2 Machine Equations 133

9.3 Field Oriented Control Using Predictive Current Control 135

*9.3.1 Discrete-Time Model* 136

*9.3.2 Control Scheme* 136

9.4 Predictive Speed Control 139

*9.4.1 Discrete-Time Model* 139

*9.4.2 Control Scheme* 140

*9.4.3 Rotor Speed Estimation* 141

9.5 Summary 142

References 143

**Part Four DESIGN AND IMPLEMENTATION ISSUES OF MODEL PREDICTIVE CONTROL**

**10 Cost Function Selection 147**

10.1 Introduction 147

10.2 Reference Following 147

*10.2.1 Some Examples* 148

10.3 Actuation Constraints 148

*10.3.1 Minimization of the Switching Frequency* 150

*10.3.2 Minimization of the Switching Losses* 152

10.4 Hard Constraints 155

10.5 Spectral Content 157

10.6 Summary 161

References 161

**11 Weighting Factor Design 163**

11.1 Introduction 163

11.2 Cost Function Classification 164

*11.2.1 Cost Functions without Weighting Factors* 164

*11.2.2 Cost Functions with Secondary Terms* 164

*11.2.3 Cost Functions with Equally Important Terms* 165

11.3 Weighting Factors Adjustment 166

*11.3.1 For Cost Functions with Secondary Terms* 166

*11.3.2 For Cost Functions with Equally Important Terms* 167

11.4 Examples 168

*11.4.1 Switching Frequency Reduction* 168

*11.4.2 Common-Mode Voltage Reduction* 168

*11.4.3 Input Reactive Power Reduction* 170

*11.4.4 Torque and Flux Control* 170

*11.4.5 Capacitor Voltage Balancing* 174

11.5 Summary 175

References 176

**12 Delay Compensation 177**

12.1 Introduction 177

12.2 Effect of Delay due to Calculation Time 177

12.3 Delay Compensation Method 180

12.4 Prediction of Future References 181

*12.4.1 Calculation of Future References Using Extrapolation* 185

*12.4.2 Calculation of Future References Using Vector Angle Compensation* 185

12.5 Summary 188

References 188

**13 Effect of Model Parameter Errors 191**

13.1 Introduction 191

13.2 Three-Phase Inverter 191

13.3 Proportional–Integral Controllers with Pulse Width Modulation 192

*13.3.1 Control Scheme* 192

*13.3.2 Effect of Model Parameter Errors* 193

13.4 Deadbeat Control with Pulse Width Modulation 194

*13.4.1 Control Scheme* 194

*13.4.2 Effect of Model Parameter Errors* 195

13.5 Model Predictive Control 195

*13.5.1 Effect of Load Parameter Variation* 196

13.6 Comparative Results 197

13.7 Summary 201

References 201

**Appendix A Predictive Control Simulation – Three-Phase Inverter 203**

A.1 Predictive Current Control of a Three-Phase Inverter 203

*A.1.1 Definition of Simulation Parameters* 207

*A.1.2 MATLAB*® *Code for Predictive Current Control* 208

**Appendix B Predictive Control Simulation – Torque Control of an Induction Machine Fed by a Two-Level Voltage Source Inverter 211**

B.1 Definition of Predictive Torque Control Simulation Parameters 213

B.2 MATLAB® Code for the Predictive Torque Control Simulation 215

**Appendix C Predictive Control Simulation – Matrix Converter 219**

C.1 Predictive Current Control of a Direct Matrix Converter 219

*C.1.1 Definition of Simulation Parameters* 221

*C.1.2 MATLAB*® *Code for Predictive Current Control with Instantaneous Reactive Power Minimization* 222

**Index 227**