主讲教师：王辉 Email：wanyaohu@163 QQ：373282509 Tel：138 7257 9612 办公室：电气实验楼三楼D304

1. Power Electronics 主讲教师：王辉 Email：wanyaohu@163.com QQ：373282509 Tel：138 7257 9612 办公室：电气实验楼三楼D304

2. Chapter 1 Introduction

3. Outline • What is power electronics? • The history • Applications • A simple example • About this course

4. What is power electronics? • Definition • Relation with information electronics • The interdisciplinary nature • Position and significance in the human society

5. Definition • Power Electronics: • A more exact explanation: is the electronics applied to conversion and control of electric power. Range of power scale : milliwatts(mW) megawatts(MW) gigawatts(GW) The primary task of power electronics is to process and control the flow of electric energy by supplying voltages and currents in a form that is optimally suited for user loads.

6. Electric Power Converter Power input Power output Control input Conversion of electric power • Other names for electric power converter: -Power converter -Converter -Switching converter -Power electronic circuit -Power electronic converter Two types of electric power Changeable properties in conversion DC(Direct Current) Magnitude AC (Alternating Current) Frequency, magnitude, number of phases or phase angle

7. Classification of power converters Power output Power input

8. Power electronic system Generic structure of a power electronic system Power Converter Power output Power input Control input Feedback/Feedforward Feedforward/Feedback Controller ( measurements of output signals ) (measurements of input signals ) Reference (commanding) Control is invariably required. Power converter along with its controller including the corresponding measurement and interface circuits, is also called power electronic system.

9. Typical power sources and loads for a power electronic system • The task of power electronics has been recently extended to also ensuring the currents and power consumed by power converters and loads to meet the requirement of electric energy sources. Power Converter Power input Power output Load Source -Electric Motor -light -heating-power converter -other electric or electronic equipment -Electric utility-battery-other electric energy source -power converter Feedback/ Feed forward Controller Reference

10. Information electronics: to process information Physical electronics: physics,material,fabrication, and manufacturing of electronic devices Vacuum electronics: using vacuum devices, e.g, vacuum tubes devices Electronics Power electronics: to process electric power Electronics Solid (Solid state) electronics: using solid state devices, e.g, semiconductor devices Electronics Applied electronics: application of electronic devices to various areas Relation with information electronics • A Classification of electronics by processing object Other classifications of electronics

11. Power Electronics Devices,circuits Static & rotating power equipment PowerElectronics Continuous, discrete Control The interdisciplinary nature William E. Newell’s description Power electronics is the interface between electronics and power.

12. Systems & Control theory Signal processing Circuit theory Simulation & computing Power electronics Electric machines Electronics Power systems Solid state physics Electromagnetics Relation with multiple disciplines • Power electronics is currently the most active discipline in electric power engineering worldwide.

13. Position and significance in the human society • Electric power is used in almost every aspect and everywhere of modern human society. • Electric power is the major form of energy source used in modern human society. • The objective of power electronics is exactly about how to use electric power, and how to use it effectively and efficiently, and how to improve the quality and utilization of electric power. • Power electronics and information electronics make two poles of modern technology and human society—— information electronics is the brain,and power electronics is the muscle.

14. The history Application of fast-switching fully-controlled semiconductor devices • The thread of the power electronics history precisely follows and matches the break-through and evolution of power electronic devices Invention of Thyristor GTO GTR Power MOSFET Thyristor (microprocessor) IGBT Power MOSFET Thyristor (DSP) Mercury arc rectifier Vacuum-tube rectifier Thyratron Power diode Thyristor late 1980s 1900 1957 mid 1970s Pre-history 1st phase 2nd phase 3rd phase

15. Applications • Industrial • Transportation • Utility systems • Power supplies for all kinds of electronic equipment • Residential and home appliances • Space technology • Other applications

16. Industrial applications • Motor drives • Electrolysis • Electroplating • Induction heating • Welding • Arc furnaces and ovens • Lighting

17. Transportation applications • Trains & locomotives • Subways • Trolley buses • Magnetic levitation • Electric vehicles • Automotive electronics • Ship power systems • Aircraft power systems

18. Utility systems applications • High-voltage dc transmission(HVDC) • Flexible ac transmission(FACTS) • Static var compensation & harmonics suppression: TCR, TSC, SVG, APF • Custom power & power quality control • Supplemental energy sources : wind, photovoltaic, fuel cells • Energy storage systems

19. Power supplies for electronic equipment • Telecommunications • Computers • Office equipment • Electronic instruments • Portable or mobile electronics computer server Telecommunication

20. Residential and home appliances • Lighting • Heating • Air conditioning • Refrigeration & freezers • Cooking • Cleaning • Entertaining

21. Applications in space technology • Spaceship power systems • Satellite power systems • Space vehicle power systems

22. Other applications • Nuclear reactor control • Power systems for particle accelerators • Environmental engineering

23. Trends • It is estimated that in developed countries now 60% of the electric energy goes through some kind of power electronics converters before it is finally used. Power electronics has been making major contributions to: --better performance of power supplies and better control of electric equipment --energy saving --environment protection reduction of energy consumption leads to less pollution reduction of pollution produced by power converters direct applications to environment protection technology

24. A simple example A simple dc-dc converter example Input source:100V Output load:50V, 10A, 500W How can this converter be realized?

25. Dissipative realization • Resistive voltage divider

26. Dissipative realization • Series pass regulator: transistor operates in active region

27. Use of a SPDT switch SPDT: Single pole double throw

28. The switch changes the dc voltage level

29. Addition of low pass filter • Addition of (ideally lossless) L-C low-pass filter, for removal of switching harmonics: Choose filter cutoff frequency f0 much smaller than switching frequency fs This circuit is known as the “buck converter”

30. Addition of control system for regulation of output voltage

31. Major issues in power electronics • How to meet the requirement of the load or gain better control of the load • How to improve the efficiency --for reliable operation of power semiconductor devices --for energy saving • How to realize power conversion with less volume, less weight, and less cost • How to reduce negative influence to other equipment in the electric power system and to the electromagnetic environment

32. Power electronics Pre-requisite course Continuing course Fundamentals of analog / digital electronics Control systems for electric drives About this course Four parts of the content Power electronic devices: Chapter 2 and 9 Power electronic circuits: Chapter 3, 4, 5 and 6 Control techniques: Chapter 7 and 8 Applications: Chapter 10 Relation with other courses

34. Arrangement • Text books - 王兆安，刘进军。《电力电子技术》。北京：机械工业出版社， 2009 - M.D Singh, K. B. Khanchandani. Power electronics, 2nd edition, Tsinghua University Press, Beijing, China,2011 • Lectures - 56 hours , bilingual teaching（English books，Chinese teaching） - After-class reading in Chinese and English will be assigned. • Labs - 10 hours, 5 projects