Chapter 1 Power Electronic Devices (Part I)

1 PowerElectronicsPowerElectronicsChapter 1 Power Electronic Devices (Part I) An introductory overview of Power Electronic An introductory overview of Power Electronic Uncontrolled device Uncontrolled device Power diodepower Half--controlled device controlled device Typical Typical fully--controlled devicescontrolled Other new Power Electronic Other new Power Electronic Drive circuit for Power Electronic Drive circuit for Power Electronic Protection of Power Electronic Protection of Power Electronic Series and parallel connections of Power Electronic Series and parallel connections of Power Electronic devicesdevicesPowerElectronics3 The concept and featuresThe concept and featuresConfiguration of systems using Power Electronic devicesConfiguration of systems using Power Electronic devicesClassificationsClassificationsMaj or topicsMajor An introductory overview

2 Of Power An introductory overview of Power Electronic deviceselectronic devicesPowerElectronics4 Power Electronic Devices : Power Electronic Devices :In broad senseIn broad senseVery often: Very often: Major material used in Power semiconductor devicesMajor material used in Power semiconductor Devices SiliconSiliconare the Electronic Devices that can be directly used in the poweare the Electronic Devices that can be directly used in the Power r processing circuits to convert or control electric circuits to convert or control electric concept of Power Electronic devicesThe concept of Power Electronic devicespower Electronic devicespower Electronic devicesVacuum Devices : Mercury arc Vacuum Devices : Mercury arc rectifier rectifier thyratronthyratron, etc.. seldom , etc.. seldom in use todayin use todaySemiconductor Devices : Semiconductor Devices .

3 Major Power Electronic devicesmajor Power Electronic devicesPower Electronic Devices = Power semiconductor devicesPower Electronic Devices = Power semiconductor devicesPowerElectronics5 Features of Power Electronic devicesFeatures of Power Electronic devicesThe electric Power that Power Electronic device The electric Power that Power Electronic device deals with is usually much larger than that the deals with is usually much larger than that the information Electronic device Electronic device working in switching states to reduce Power Usually working in switching states to reduce Power losseslossesp=vi=0 Off-stateCurrent through the device is 0i=0p=vi=0On-stateVoltage across the device is 0v=0 PowerElectronics6 Features of Power Electronic devicesFeatures of Power Electronic devicesNeed to be controlled by information Electronic to be controlled by information Electronic often, drive circuits are necessary to interface Very often, drive circuits are necessary to interface between information circuits and Power information circuits and Power Power loss usually larger than information Dissipated Power loss usually larger than information Electronic Devices Electronic Devices special packaging and heat sink special packaging and heat sink are losses on Power semiconductor Power losses on Power semiconductor devicesdevices= conduction loss + turn= conduction loss + turn--off loss + offoff loss + off--state loss + turnstate loss + turn--on losson lossO n -s ta te(conduction state)tu rn in g -offOff-state(blocking state)

4 Tu rn in g-o ntttvipTotal Power loss onTotal Power loss onpower semiconductorpower semiconductorSwitching lossSwitching loss(on(on--state loss)state loss)PowerElectronics8 Configuration of systems using Power Configuration of systems using Power Electronic deviceselectronic devicesControl circuitdetectioncircuitdrivecircuitPower circuit( Power stage,main circuit)Control circuit (in a broad sense) Power Electronic system:Electric isolation:optical, magneticProtection circuit is also very often used in Power electronicsystem especially for the expensive Power of a Power Electronic deviceTerminals of a Power Electronic deviceCEGA Power Electronic device must have at least two terminals to allow Power circuit current flow Power Electronic device usually has a third terminal control terminal to control the states of the signal from drive circuit must be connected between the Control signal from drive circuit must be connected between the control terminal and a fixed Power circuit terminal (therefore control terminal and a fixed Power circuit terminal (therefore called common terminal ).)

5 Called common terminal ).Drive CircuitPowerElectronics10A classification of Power Electronic devicesA classification of Power Electronic devicesUncontrolled device: diodeUncontrolled device: diode(Uncontrollable device)(Uncontrollable device)FullyFully--controlled device: Power MOSFET, IGBT,GTO, IGCT controlled device: Power MOSFET, IGBT,GTO, IGCT(Fully(Fully--controllable device)controllable device)HalfHalf--controlled device:controlled device:thyristorthyristor(Half(Half--con trollable device)controllable device)has only two terminals and can not be controlled by control signal. The on and off states of the device are determined by the Power turned-on by a control signal and turned-off by the Power circuitThe on and off states of the device are controlled by control classificationsOther classificationspower Electronic devicespower Electronic devicesPulsePulse--triggered devicestriggered devicesLevelLevel--sensitive (levelsensitive (level--triggered) devicestriggered) devicespower Electronic devicespower Electronic devicespower Electronic devicespower Electronic devicesCurrentCurrent--driven (currentdriven (current--controlled) devicescontrolled) devicesVoltageVoltage--driven (voltagedriven (voltage--controlled) Devices controlled) Devices (Field(Field--controlled Devices )controlled Devices )UnipolarUnipolardevices (Majority carrier Devices ) Devices (Majority carrier Devices )

6 Composite devicesComposite devicesBipolar Devices (Minority carrier Devices )Bipolar Devices (Minority carrier Devices )PowerElectronics12 Appearance, structure, and symbol Appearance, structure, and symbol Physics of operationPhysics of operationCharacteristicsCharacteristicsS pecificationSpecificationSpecial issuesSpecial issuesDevices of the same familyDevices of the same familyMajor topics for each deviceMajor topics for each deviceSwitching characteristicsSwitching characteristicsStatic characteristicsStatic characteristicsPowerElectronics13 Passive components in Power Electronic Passive components in Power Electronic circuitcircuitTransformer, inductor, capacitor and resistor:Transformer, inductor, capacitor and resistor:these are passive components in a Power Electronic these are passive components in a Power Electronic circuit since they can not be controlled by control signal and circuit since they can not be controlled by control signal and their characteristics are usually constant and characteristics are usually constant and requirements for these passive components by Power The requirements for these passive components by Power Electronic circuits could be very different from those by Electronic circuits could be very different from those by ordinary Uncontrolled device Power Uncontrolled device Power diodeAppearanceAppearanceStructureStruct ureSymbolSymbolCathodeAnodeKKAAA nodeCathodePowerElectronics15PN junctionPN junction- - - - - - - - - - - - - - - + + + + + + + + + + + + + + + +-+-+-+-+-p regionn regionDirection ofinner

7 Electric fieldSpace charge region(depletion region,potential barrierregion)Semiconductor (Column IV element, Semiconductor (Column IV element, SiSi))Electrons and and semiconductor (intrinsic semiconductor)Pure semiconductor (intrinsic semiconductor)Doping, pDoping, p--type semiconductor. Ntype semiconductor. N--type semiconductortype semiconductorPN junctionPN junctionEquilibrium of diffusion and driftEquilibrium of diffusion and driftPowerElectronics16PN junction with voltage applied in the PN junction with voltage applied in the forward directionforward directionV+++++-----npWoW+-PowerElectron ics17PN junction with voltage applied in the reverse PN junction with voltage applied in the reverse directiondirection+-V+++++--------+++npW oWEffective directionof Electronic fieldPowerElectronics18 Construction of a practical Power diodeConstruction of a practical Power diodeFeatures different from lowFeatures different from low-- Power (information Electronic ) diodespower (information Electronic ) diodes Larger size Vertically oriented structure n drift region (p-i-n diode)

8 Conductivity modulation250 mBreakdown voltage dependent10 mpNd=10 cmn substrate-319Na=10 cm-319+n epiNd=10 cm-314pNd=10 cmn substrate-319+Na=10 cm-319+n epi-Nd=10 cm-314iAnodeCathode+-V-PowerElectronics1 9 ForwardForward--biased Power diodebiased Power diodePowerElectronics20 ReverseReverse--biased Power diodebiased Power diodeBreakdownBreakdown Avalanche breakdown Thermal breakdownPowerElectronics21 The positive and negative charge in the depletion region is The positive and negative charge in the depletion region is variable with the changing of external with the changing of external voltage. Junction capacitor CJunction capacitor capacitor CJunction capacitor CJJJ unction capacitor influences the switching characteristics of Junction capacitor influences the switching characteristics of Power diode. Power diode.

9 Junction capacitorJunction capacitorDiffusion capacitor Diffusion capacitor CCDDP otential barrier capacitor Potential barrier capacitor CCBBP owerElectronics22 Static characteristics of Power diodeStatic characteristics of Power diodeThe IThe I--V characteristic of Power diode V characteristic of Power diode IOIFUTOUFUP owerElectronics23 Switching (dynamic) characteristics of Power Switching (dynamic) characteristics of Power diodediodeReverseReverse--recovery process:recovery process:Reverse-recovery time, reverse-recovery charge, reverse-recovery peak transientoff transientIFUFtFt0trrtdtft1t2tURURPIRPdiF dtdiRdtPowerElectronics24 Switching (dynamic) characteristics Switching (dynamic) characteristics of Power of Power diodediodeForward recovery process:Forward recovery process:forward-recovery timeTurnTurn--on transienton transientUFPuiiFuFtfrt02 VPowerElectronics25 Specifications of Power diodeSpecifications of Power diodeAverage rectified forward current IAverage rectified forward current IF(AV)F(AV)Forward voltage UForward voltage UFFPeak repetitive reverse voltage UPeak repetitive reverse voltage URRMRRMM aximum junction temperature TMaximum junction temperature TJMJMR everseReverse--recovery time recovery time ttrrrrPowerElectronics26 Types of Power diodesTypes of Power diodesGeneral purpose diode (rectifier diode):General purpose diode (rectifier diode):Fast recovery diodeFast recovery diodeSchottkySchottkydiode (diode (SchottkySchottkybarrier diodebarrier diode--SBD)SBD)standard recoveryReverse recovery time and charge specified.

10 Trris usually less than 1 s, for many less than 100 ns ultra-fast recovery diode. A majority carrier device Essentially no recovered charge, and lower forward voltage. Restricted to low voltage (less than 200V)PowerElectronics27 Examples of commercial Power diodesExamples of commercial Power diodesPowerElectronics28 History and applications of Power diodeHistory and applications of Power diodeApplied in industries starting 1950sApplied in industries starting 1950sStill inStill in--use today. Usually working with controlled use today. Usually working with controlled Devices as necessary componentsdevices as necessary componentsIn many circumstances fast recovery diodes or In many circumstances fast recovery diodes or schottkyschottkydiodes have to be used instead of general diodes have to be used instead of general purpose Half--controlled devicecontrolled device ThyristorThyristorAnother name: SCRA nother name.