2 Outline What is power electronics? The history Applications A simple exampleAbout this course
3 What is power electronics? DefinitionRelation with information electronicsThe interdisciplinary naturePosition and significance in the human society
4 Definition Power Electronics: A more exact explanation:is the electronics applied to conversion and control ofelectric power.Range of power scale :milliwatts(mW) megawatts(MW) gigawatts(GW)The primary task of power electronics is to process andcontrol the flow of electric energy by supplying voltagesand currents in a form that is optimally suited for userloads.
5 Conversion of electric power ConverteroutputinputControl inputOther names for electricpower converter:-Power converter-Converter-Switching converter-Power electronic circuit-Power electronic converterTwo types of electric powerChangeable properties in conversionDC(Direct Current)MagnitudeAC (Alternating Current)Frequency, magnitude,number of phases
6 Classification of power converters DCACAC to DC converter (Rectifier)AC to AC converter( Fixed frequency : AC controllerVariable frequency: Cycloconverter or frequency converter)DC to DC converter (Chopper)DC to AC converter(Inverter)Power outputPower input
7 Power electronic system Generic structure of a power electronic systemPower ConverterPower inputPower outputControl inputFeedback/FeedforwardFeedforward/FeedbackController( measurements of output signals )( measurements of input signals )Reference(commanding)Control is invariably required.Power converter along with its controller including thecorresponding measurement and interface circuits, isalso called power electronic system.
8 Typical power sources and loads for a power electronic system ConverterPower inputPower outputLoadSource-Electric utility -battery -other electric energy source -power converter-Electric Motor-light-heating -power converter -other electric or electronic equipmentFeedback/Feed forwardControllerReferenceThe 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.
9 Relation with information electronics A Classification of electronics by processing objectElectronicsInformation electronics: to process informationPower electronics: to process electric powerElectronicsVacuum electronics: using vacuum devices,e.g, vacuum tubes devicesSolid (Solid state) electronics: using solid state devices,e.g, semiconductor devicesApplied electronics: application of electronicdevices to various areasPhysical electronics: physics,material,fabrication,and manufacturing of electronicdevicesOther classifications of electronics
10 The interdisciplinary nature William E. Newell’s descriptionElectronicsDevices,circuitsPowerStatic & rotating power equipmentPower ElectronicsContinuous, discrete ControlPower electronics is the interface betweenelectronics and power.
11 Relation with multiple disciplines PowerelectronicsSystems &Control theoryCircuittheorySignal processingSimulation & computingElectronicsSolid state physicsElectromagneticsPower systemsElectric machinesPower electronics is currently the most activediscipline in electric power engineering worldwide.
12 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.
13 Mercury arc rectifier Vacuum-tube rectifier Thyratron The historyApplication of fast-switching fully-controlled semiconductor devicesInvention of ThyristorGTOGTRPower MOSFETThyristor(microprocessor)Mercury arc rectifier Vacuum-tube rectifier ThyratronIGBTPower MOSFETThyristor(DSP)Power diode Thyristorlate 1980s19001957mid 1970sPre-history1st phase2nd phase3rd phaseThe thread of the power electronics history precisely follows and matches the break-through and evolution of power electronic devices
14 Applications Industrial Transportation Utility systems Power supplies for all kinds of electronic equipmentResidential and home appliancesSpace technologyOther applications
15 Industrial applications Motor drivesElectrolysisElectroplatingInduction heatingWeldingArc furnaces and ovensLighting
16 Transportation applications Trains & locomotivesSubwaysTrolley busesMagnetic levitationElectric vehiclesAutomotive electronicsShip power systemsAircraft power systems
17 Utility systems applications High-voltage dc transmission(HVDC)Flexible ac transmission(FACTS)Static var compensation & harmonics suppression: TCR, TSC, SVG, APFCustom power & power quality controlSupplemental energy sources :wind, photovoltaic, fuel cellsEnergy storage systems
18 Power supplies for electronic equipment TelecommunicationsComputersOffice equipmentElectronic instrumentsPortable or mobile electronicscomputerserverTelecommunication
19 Residential and home appliances LightingHeatingAir conditioningRefrigeration & freezersCookingCleaningEntertaining
20 Applications in space technology Spaceship power systemsSatellite power systemsSpace vehicle power systems
21 Other applications Nuclear reactor control Power systems for particle acceleratorsEnvironmental engineering
22 TrendsIt 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 majorcontributions to:--better performance of power supplies and better control ofelectric equipment--energy saving--environment protectionreduction of energy consumption leads to less pollutionreduction of pollution produced by power convertersdirect applications to environment protection technology
23 A simple example A simple dc-dc converter example Input source:100V Output load:50V, 10A, 500WHow can this converter be realized?
24 Dissipative realization Resistive voltage divider
25 Dissipative realization Series pass regulator:transistor operates in active region
26 Use of a SPDT switchSPDT: Single pole double throw
28 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 thanswitching frequency fsThis circuit is known as the “buck converter”
29 Addition of control system for regulation of output voltage
30 Major issues in power electronics How to meet the requirement of the load or gain better control of the loadHow to improve the efficiency--for reliable operation of power semiconductor devices--for energy savingHow to realize power conversion with less volume, less weight, and less costHow to reduce negative influence to other equipment in the electric power system and to the electromagnetic environment
31 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 10Relation with other coursesFundamentalsof analog / digitalelectronicsPre-requisite courseControl systemsfor electricdrivesContinuing coursePowerelectronics
32 Arrangement Text books Lectures - 48 hours , all in English Labs - 王兆安，刘进军。《电力电子技术》。北京：机械工业出版社， 2009- N. Mohan, T. M. Undeland, W. P. Robbins. Power edectronics: converter, applications, and Design, 3rd edition, John Wiley & Sons, New York, 2003, Higher Education Press, Beijing, China, 2004Lectures- 48 hours , all in English- After-class reading in Chinese and English will be assigned.Labs- 8 hours, 5 projects