IGBT保护分析(英飞凌)

Over-temperature,Over–current&Over-voltageprotectioninIGBTapplicationPage2Copyright©InfineonTechnologies2007.Allrightsreserved.22.05.2007ForinternaluseonlyOver–temperatureTypeAmbienttemperature-TaHeatsinktemperature-ThBaseplatetemperature-TcJunctiontemperature-TjInlet/outlettemperatureThThWithoutbaseplateTcreferenceWithbaseplateThThPage3Copyright©InfineonTechnologies2007.Allrightsreserved.22.05.2007ForinternaluseonlyOver–temperatureTa–dependsonexternalcoolingapplication,limitofcomponentsinthecabinetinside.Sometimes,MaxallowableTa=50oC,or40oC(typical)Th-dependsonthecoolingcapabilityanddesignforthepowerdissipationbasedontherealapplication.Tc–dependsoncasetemperature,anddeterminedbythenominalcurrentdefinition(Tc=100oC,or85oC)Tj-max.allowableoperationalTvjop(125oC/150oC).Page4Copyright©InfineonTechnologies2007.Allrightsreserved.22.05.2007ForinternaluseonlyModuleNTCfortemperaturemeasurementCeramicHeatconductingpasteThTCTJIGBTTNTCThTCTJIGBTTNTCNTC-temperatureforamodulewithabase-plateNTC-temperatureforamodulewithoutabase-platethJCJIGBTNTCRPKTTmax10thJCJIGBTNTCRPKTTmax15Correctionfactorbasedontheheatspreadofthemodule-constructionThecorrectionfactorcouldbedifferentfordifferentmodules.ItdependsonthepositionoftheNTC.Page5Copyright©InfineonTechnologies2007.Allrightsreserved.22.05.2007ForinternaluseonlyModuleNTCvs.Tj544148585353TJ[°C]34TNTC[°C]FP75R12KE3Page6Copyright©InfineonTechnologies2007.Allrightsreserved.22.05.2007ForinternaluseonlyFailureOverTemperatureSolderbelowtheIGBTispouredoutLargeAreasoftheAluminumLayeraremolten.TypicalBeads.BubblesintheImideslayerPage7Copyright©InfineonTechnologies2007.Allrightsreserved.22.05.2007ForinternaluseonlySafetyisolationTemperaturemeasurement┐IsolatedSigma-DeltaconverterExample:AD7400Sigma-Deltamodulator┐HighprecisionV-Fconverter+OptocouplerExample:LM231┐Highprecisiontimer+OptocouplerExample:SA555┐LinearoptocouplerExample:IL300Page8Copyright©InfineonTechnologies2007.Allrightsreserved.22.05.2007ForinternaluseonlySafetyIsolation–LinearoptocouplerBuilt-inNTCThermistorinModulePage9Copyright©InfineonTechnologies2007.Allrightsreserved.22.05.2007ForinternaluseonlyOver-currentprotectionPhase1Phase2Phase1:RBSOAOCprotectionarea.Phase2:ForbiddenSOASCstartingpoint.Page10Copyright©InfineonTechnologies2007.Allrightsreserved.22.05.2007ForinternaluseonlyIGBTProtection-SCLimit&Turn-offClampingtheGateVoltagelimitthepeakSCcurrentSwitchoffIGBTafterSCcurrentisstablelowerSCcurrent,lowerdi/dt2-stepTurn-offfirstreducegatedrivingvoltagelowerSCcurrent,longerSCtimeSoftTurn-offlowerdi/dtCurrentIcVoltageVceDoNotSwitchOffAtThisMomentSwitchOfftheSC!Page11Copyright©InfineonTechnologies2007.Allrightsreserved.22.05.2007ForinternaluseonlyIGBTProtection-Over-currentprotectionFP15R12W1T4FP10R12W1T4OvercurrentsettingpointofIc=2*Icnom,relatedtorealTvj.op.MostlyOCsettingisclosetoIcnom.Page12Copyright©InfineonTechnologies2007.Allrightsreserved.22.05.2007ForinternaluseonlyIGBTProtection-Over-voltageofVGE&VCEVGEovervoltagecanbetheresultofESD,powersupplyfaultorchargingofMillercapacitorviaRg_OFF.Itcandamagethegate(VGEVGES)orcausetheSCcurrenttodrasticallyincrease.PossiblecausesofVCEovervoltage:-FastSCturn-off&highstrayinductance(Solutions:softshut-down,turn-offdelay)-Re-generativebraking(Solution:brakechopper)-FluctuationoflinevoltagePage13Copyright©InfineonTechnologies2007.Allrightsreserved.22.05.2007ForinternaluseonlyIGBTProtection-OvervoltageofVge&VceToprotectgate&limitSCcurrent…Page14Copyright©InfineonTechnologies2007.Allrightsreserved.22.05.2007ForinternaluseonlyIGBTswitchingon/offprocessmax)*(VcedtdiLVVccccesPage15Copyright©InfineonTechnologies2007.Allrightsreserved.22.05.2007ForinternaluseonlyOver-voltagereductionUseappropriatesnubbercircuittosuppresstheovervoltage;AdjusttheVge/Rgtodecreasethedi/dt;Selectthelowimpedancecapacitors;PlacethecapacitorascloseasIGBTmoduletoreducetheloopinductance;ConnectthepowerandsnubberloopwithIGBTmoduleasshortaspossible;Page16Copyright©InfineonTechnologies2007.Allrightsreserved.22.05.2007ForinternaluseonlyGeneralRCDsnubberRCDsnubber,otherRCandRCDsnubbers:•CanrealizeevensmallerVcepeakthanRCDsnubber.•SnubberRwouldhaveverybigpowerdissipation.•LowimpedanceRishardtofind.•WillnotinfluenceIGBTturnon•HugelossesonsnubberR•QuitehardtofindasuitableRvalue,whenswitchingfrequencyishighBeusedbelowhundredsWattapplicationSeldomusedPage17Copyright©InfineonTechnologies2007.Allrightsreserved.22.05.2007ForinternaluseonlyCSnubbercircuitLδ2Lδ-OVreductionCpositionisclosetopowerterminalsaspossible.Page18Copyright©InfineonTechnologies2007.Allrightsreserved.22.05.2007ForinternaluseonlyLoop(DCcapacitor,Csnubber)L1:DCcapacitorinductance+busbarinductanceL2:moduleterminaltosnubbercapacitorinductanceL31/L32:Upper/BottomIGBTinternalstrayinductanceL4:snubbercapacitorinternalstrayinductanceLoopA:busLCoscillationloopLoopB:commutationloopthroughsnubberPage19Copyright©InfineonTechnologies2007.Allrightsreserved.22.05.2007ForinternaluseonlyOver-voltageprotection∆V3T/2∆V2Vcc∆V1tid