Power Electronics

Ned Mohan is Oscar A. Schott Professor of Power Electronics in the Department of Electrical Engineering at the University of Minnesota, where he has been teaching for 33 years. He has written five textbooks; one of them is translated into several languages. He has 13 patents and has written over 200 technical articles. He is actively involved in the area of renewable energy and is working on the next generation of wind generators and storage. He received the Distinguished Teaching Award by the Institute of Technology at the University of Minnesota. He is a Morse-Alumni Distinguished Teaching Professor and is a member of the Academy of Distinguished Teachers at the University of Minnesota. He received the Outstanding Educator Award from the Power Engineering Society of the IEEE in 2008. He is a Fellow of the IEEE.

PREFACE xiii CHAPTER 1 POWER ELECTRONICS: AN ENABLING TECHNOLOGY 1 1.1 Introduction to Power Electronics 1 1.2 Applications and the Role of Power Electronics 2 1.3 Energy and the Environment: Role of Power Electronics in Providing Sustainable Electric Energy 4 1.4 Need for High Efficiency and High Power Density 8 1.5 Structure of Power Electronics Interface 9 1.6 Voltage-Link-Structure 11 1.7 Recent and Potential Advancements 16 References 16 Problems 17 CHAPTER 2 DESIGN OF SWITCHING POWER-POLES 21 2.1 Power Transistors and Power Diodes 21 2.2 Selection of Power Transistors 22 2.3 Selection of Power Diodes 24 2.4 Switching Characteristics and Power Losses in Power-Poles 25 2.5 Justifying Switches and Diodes as Ideal 30 2.6 Design Considerations 30 2.7 The PWM IC 33 References 33 Problems 34 Appendix 2A Diode Reverse-Recovery and Power Losses 35 CHAPTER 3 SWITCH-MODE DC-DC CONVERTERS: SWITCHING ANALYSIS, TOPOLOGY SELECTION AND DESIGN 38 3.1 DC-DC Converters 38 3.2 Switching Power-Pole in DC Steady State 38 3.3 Simplifying Assumptions 42 3.4 Common Operating Principles 43 3.5 Buck Converter Switching Analysis in DC Steady State 43 3.6 Boost Converter Switching Analysis in DC Steady State 45 3.7 Buck-Boost Converter Analysis in DC Steady State 50 3.8 Topology Selection 56 3.9 Worst-Case Design 57 3.10 Synchronous-Rectified Buck Converter for Very Low Output Voltages 57 3.11 Interleaving of Converters 58 3.12 Regulation of DC-DC Converters by PWM 58 3.13 Dynamic Average Representation of Converters in CCM 59 3.14 Bi-Directional Switching Power-Pole 61 3.15 Discontinuous-Conduction Mode (DCM) 62 References 68 Problems 68 CHAPTER 4 DESIGNING FEEDBACK CONTROLLERS IN SWITCH-MODE DC POWER SUPPLIES 74 4.1 Introduction and Objectives of Feedback Control 74 4.2 Review of Linear Control Theory 75 4.3 Linearization of Various Transfer Function Blocks 77 4.4 Feedback Controller Design in Voltage-Mode Control 83 4.5 Peak-Current Mode Control 86 4.6 Feedback Controller Design in DCM 91 References 93 Problems 93 Appendix 4A Bode Plots of Transfer Functions with Poles and Zeros 94 Appendix 4B Transfer Functions in Continuous Conduction Mode (CCM) (on accompanying website) 97 Appendix 4C Derivation of Parameters of the Controller Transfer Functions (on accompanying website: www.wiley.com/college/mohan) 97 CHAPTER 5 RECTIFICATION OF UTILITY INPUT USING DIODE RECTIFIERS 98 5.1 Introduction 98 5.2 Distortion and Power Factor 99 5.3 Classifying the "Front-End" of Power Electronic Systems 107 5.4 Diode-Rectifier Bridge "Front-Ends" 107 5.5 Means to Avoid Transient Inrush Currents at Starting 113 5.6 Front-Ends with Bi-Directional Power Flow 114 Reference 114 Problems 114 CHAPTER 6 POWER-FACTOR-CORRECTION (PFC) CIRCUITS AND DESIGNING THE FEEDBACK CONTROLLER 116 6.1 Introduction 116 6.2 Operating Principle of Single-Phase PFCs 116 6.3 Control of PFCs 119 6.4 Designing the Inner Average-Current-Control Loop 120 6.5 Designing the Outer Voltage-Control Loop 122 6.6 Example of Single-Phase PFC Systems 124 6.7 Simulation Results 125 6.8 Feedforward of the Input Voltage 125 6.9 Other Control Methods for PFCs 125 References 127 Problems 127 Appendix 6A Proving that ^Is3 ^IL2 1/4 12 128 Appendix 6B Proving that ~vd ~iL dsTH 1/4 1 2 V^s Vd R=2 1 th sdR=2THC 129 CHAPTER 7 MAGNETIC CIRCUIT CONCEPTS 130 7.1 Ampere-Turns and Flux 130 7.2 Inductance L 131 7.3 Faraday's Law: Induced Voltage in a Coil Due to Time-Rate of Change of Flux Linkage 133 7.4 Leakage and Magnetizing Inductances 134 7.5 Transformers 136 Reference 139 Problems 139 CHAPTER 8 SWITCH-MODE DC POWER SUPPLIES 141 8.1 Applications of Switch-Mode DC Power Supplies 141 8.2 Need for Electrical Isolation 142 8.3 Classification of Transformer-Isolated DC-DC Converters 142 8.4 Flyback Converters 142 8.5 Forward Conve