IGBT-Gate-driver-design-for-T4-Training-Applicatio

1NorbertPluschke10012NorbertPluschke1001IGBTdriverprinzipleIGBTisavoltagecontrolleddeviceandneedsaGate-EmitterVoltagetoturnonandturnoff.ThegateresistorlimitstheChargingprocessofthecapacitorsoftheIGBTThisconfigurationhasdifferentGatecurrentforturnonandoffRgon=Rg1parallelRg2Rgoff=Rg1only3NorbertPluschke1001SelectionofthegateresistorWhichgatedriverissuitableforthemoduleSKM400GB126D?Firstselectthegateresistoraccording“reverserecoverycurrentdiode”Designparameters:fsw=10kHzRg=?reverserecoverycurrentDiodeshouldbe-1.5xIdiodeby80degreecase270Ax1.5=405A4NorbertPluschke1001SelectionofgateresistorWhichgatedriverissuitableforthemoduleSKM400GB126D?Secondcomparethe“recommendedgateresistor”withyourgateresistorformfirststepGateresistorinrangeof“test–gateresistor”Inthiscase2Ohm5NorbertPluschke1001Howtofindtherightgateresistor?Rg=2OhmTwogateresistorsarepossibleforturnonandturnoffRon=2OhmRoff=5Ohm(lowervoltageovershoot)195A–maxreverserecoverycurrentThethicklineisthereverserecoveringcurrentif“Rgon”istoosmall,thepeakcurrentishighandoscillationtoolarge.Weshouldavoidoscillation.Thethinlineisthereverserecoveringcurrentif“Rgon”issuitable–similartorecommendedRgindatasheet6NorbertPluschke1001-8152230nCDeterminationofGateChargeGatecharge(QG)canbedeterminedfromfig.6oftheSEMITRANSdatasheet⇒QG=2230nCFromthefig.Weknowthatthegatedriverchangesbetween-8Vand+15V.Theenergycanbereadas:Thetypicalturn-onandturn-offvoltageofthegatedriverisVGG+=+15VVGG-=-8V7NorbertPluschke1001CalculationoftheaveragecurrentCalculationofaveragecurrent:IoutAV=P/ΔUΔV=+Vg+[-Vg]withP=E*fsw=QG*ΔV*fsw⇒IoutAV=QG*fsw=2230nC*10kHz=22.3mAAbsolutevalueThepowersupplymustbesuitabletoprovidethiscurrent8NorbertPluschke1001CalculationofthepeakgatecurrentExaminationofthepeakgatecurrentwithminimumgateresistanceÎE.g.RG.on=RG.off=2ΩÎIg.puls≈ΔV/RG+Rint=23V/(2Ω+2Ω)=5.75AChipresistance(datasheet)Thepeakcurrentcanbesuppliedbya“capacitor”closetotheIGBTdriver(10-100uF)Incombinationwithasmallceramiccapacitorinparallel(10nF)9NorbertPluschke1001ChoiceofthesuitablegatedriverTheabsolutemaximumratingsofthesuitablegatedrivermustbeequalorhigherthantheappliedandcalculatedvaluesÎGatechargeQG=2230nCÎAveragecurrentIoutAV=22.3mAÎPeakgatecurrentIg.pulse=5.75AÎSwitchingfrequencyfsw=10kHzÎCollectorEmittervoltageVCE=1200VÎNumberofdriverchannels:2(GBmodule)Îdualdriver10NorbertPluschke1001ConsidertheturnonandturnoffdelayGateresistorhasaninfluenceTurnontime(di/dt)TurnondelayTurnofftime(dv/dt)TurnoffdelayGateresistorcancreateacrossconductionifturnondelayandturnoffdelaytotaldifferentGateresistorwillinfluencethe“realdeadtime”betweentopandbottomIGBT11NorbertPluschke1001DeadtimecalculationturnonOntheconditionthattheinputsignalandthecollectorcurrentstartfrom0.TimedifferencebetweentheinputsignalriseTo90%ofhighlevelvoltageandthecollectorcurrentrisetothe10%ofthesteadyoperatingcurrentmeansturnondelaytime.(TDON)Wheninputsignalrisefrom0tohighlevel，ThecollectorcurrentwouldnotriseimmediatelyTurnondelaytimeincludePWMsignaltransmissiondelayoftheIGBTdriverIGBTturnondelaytimeitself12NorbertPluschke1001DeadtimecalculationturnoffOntheconditionthattheinputsignalandthecollectorcurrentstartfromsteady“high”.TimedifferencebetweentheinputsignalfallTo90%ofhighlevelvoltageandthecollectorcurrentfalltothe10%ofthesteadyoperatingcurrentmeansturnondelaytime.(TDoff)Wheninputsignalrisefrom0tohighlevel，ThecollectorcurrentwouldnotriseimmediatelyTurnoffdelaytimeincludePWMsignaltransmissiondelayoftheIGBTdriverIGBTturnoffdelaytimeitself13NorbertPluschke1001GateResistorInfluenceindelayUGE1istheG-EvoltageofDiethatthegateresistoris3.4OhmUGE2istheG-EvoltageofDiethatthegateresistoris1.3OhmThedifferenceofgateresistorsinfluentslightlytherisetimeandturnondelaytimeofVgewaveform.ButitgreatlyinfluenttheturnoffthedelaytimeandfalltimeofVgewaveform.14NorbertPluschke1001GateResistorsInfluenceinDelayDifferentgateresistorsinfluenttheturnoffdelaytimemorethantheturnondelaytime.Tothetopandbuttomstructure,itwillinfluentthedeadtimeandcrossconductionshouldbeconsidered.15NorbertPluschke1001DeadtimeexplanationExample:Deadtime=3uslogiclevelTurnondelay1usTurnoffdelay2.5usTd–toffdelay+tondelay=realdeadtimeRealdeadtime:3us–2.5us+1us=1.5usMaybetooshort–1.5usCheckthedelayforturnonandturnofftoavoidcrossconductionConsidertheValueoftheGateResistor(Turnon,turnoffdelay)16NorbertPluschke1001ProtecttheGateEmitterDistance–allIGBTDriverRg1Cge=CissMustbeverycloseTotheIGBTRge=4.7–10kOhmZ-Diode=16.8–17.5V17NorbertPluschke100118NorbertPluschke1001WhichIGBTdriver?IGBTdriverforlowpower220VAC----bootstrapIGBTdriver,pulsetransformerIGBTdriver,DCbusvoltagedriver400VAC----newbootstrapIGBTdriverandsimpleopticalcouplerIGBTdriverIGBTdriverformediumpower400VAC----opticalcouplerwithbooster690VAC----pulsetransformerforisolationandcomplexIGBTdriverIGBTdriverforhighpowerIGBTdriverwithtransformerforisolationIGBTdriverwithVcemonitoring,softturnoffbehavior,differentgateresistorforturnonandturnoff,19NorbertPluschke1001Bootstrapdriver–noisolationBootstrapAdvantage：Simplecircuitdesign.Noneedindependentpowersupplyfo