双向DCDC变换器软开关

1、 #1.4244-0714-1.07/S20.00C2007IEEE. ANewZVSBidirectionalDC-DCConverterWithPhase-ShiftPlusPWMControlSchemeHuafengXiao,LiangGuo,ShaojunXieCollegeofAutomationEngineering,NanjingUniversityofAeronauticsandAstronauticsNanjing,210016,China #1.4244-0714-1.07/S20.00C2007IEEE. # 1.4244-0714-1.07/S20.00C2007IE

2、EE. #Abstract-Thecurrent-voltage-fedbidirectionalDC-DCconvertercanrealizeZVSfortheswitcheswiththeuseofthephase-shift(PS)technology,howeverthecurrent-fedswitchessufferfromhighvoltagespikeandhighcirculatingconductionlosses.Inordertosolvetheseproblems,anovelphase-shiftplusPWM(PSP)controlZVSbi-direction

3、alDC-DCconverterisproposed,whichadoptsactiveclampingbranchandPWMtechnologyThenovelconvertercanrealizeZVSforallpowerswitchesfromnoloadtofullloadTheoperationprincipleisanalyzedandverifiedbya28V/270Vconversionprototyperatedat1.5kW.IntroductionInrecentyearsthedevelopmentofhighpowerisolatedbidirectionald

4、c-dcconverters(BDC)hasbecomeanimportanttopicbecauseoftherequirementsofelectricvehicle,uninterruptiblepowersupply(UPS)andaviationpowersystem1-7.InatypicalUPSsystem,thebuMcryischargedwhenthemainpowersourceisnormalandthebatterydischargestosupplypowerintheeventofloseofmainpowersourceIntheaircrafthighvol

5、tagedirectcurrent(HVDC)powersupplysystem,whenthe270VHVDCgeneratorisingear,itchargesthe28Vbatteryandsuppliesthe28VkeyloadbytheBDC.andwhenthegeneratorisinfailure,the28Vbatterydischargestosupply270VkeyloadbytheBDC.Thehigh-lowvoltageconversionandelectricalisolationarenecessaryinabove-mentionedcondition.

6、Thecurrent-voltage-fedBDCisfitforsuchsystemduetoithasahighvoltageconversionratioandlowcurrentripple.Adualactivefullbridgedc-dcconverterwasproposedforhighpowerBDC4,5J,whichemploystwovoltage-fedinverterstodriveeachsidesofatransforme匚ItssymmetricstructureenablesthebidirectionalpowerflowandZVSforallswit

7、chesAdualactivehalfbridgecurrent-voltage-fedsoft-switchingbidirectionaldc-dcconverterwasproposedwithreducedpowercomponents6,however,thecurrent-fedhalfbridgesuffersfromahighvoltagespikebecauseoftheleakageinductanceofthetransformc匚Whenthevoltageamplitudeofthetwosidesofthetransformerisnotmatched,thecur

8、rentstressesandcirculatingconductionlossesbecomehigherin4,5,and6.Inaddition,theseconverterscannotachieveZVSinlow-loadcondition.ThesedisadvantagesmakeitnotsuitableforlargevariationofinputoroutputvoltageconditionAnasymmetrybidirectionaldc-dcconverterwithPhaseshiftplusPWM(PSP)controlwasproposedin7,thec

9、irculatingconductionlosseisreduced,however,itresultsacurrentbiaswhichdecreasestheutilizationofthetransformcr.Acurrent-voltage-fedPSPZVSBDCbasedonanisolateddualboostconverterandahalfbridgeconverterisproposed,asshowninFig.l(a).TheconverterwithanactiveclampingbranchSal,Sa2andCcavoidsthevoltagespike,ach

10、ievesZVSofSIandS2,andalsorestrainsthestart-innishcurrent8.ByPWMcontrolofSIandS2,VabandVcdarewellmatched,whichreducescirculatingconductionlosses,alsorealizesZVSfromnoloadtofullloadThedecouplingcontrolofPhase-shift(PS)andPWMisrealizedbytwoindependenceclose-loopscontrolcircuitsTheoperationprincipleisan

11、alyzedindetail.A22-32V/270V1.5kWprototypeisbuilttoverifytheoperationprincipleoftheproposedconvener.OperationPrincipleTheBDChastwooperationmodes,theenergyflowingfromVsidetoV2sideisdefinedasBoostmode,andthecounterpartisdefinedasBuckmodeBeforetheanalysis,thefollowingassumptionsaregiven:1)Alltheactivepo

12、werdevicesarcidealswitcheswithparallelbodydiodesandparasiticcapacitors,2)TheinductanceLandL2arelargeenoughtobetreatedastwocurrentsourceswithvalueof0.5/bThetransformerTisidealonewithseriesleakageinductorJ.Fig.l(b)showsthekeywaveformsintheBoostmode.Onecompleteswitchingcyclecanbedividedintotenperiods.B

13、ecauseofthesimilarity,onlyahalfswitchingcycleisdescribedindetail.TheequivalentcircuitsarcshowninFig.2Becausethetwosidesofthetopologyarcsymmetrical,theoperationprinciplesinBuckmodearesimilartothoseinBoostmodeFig.l(c)showsthekeywaveformsintheBuckmode.Stage0Before/():RefertoFig.2(a).SbSa2andS4areconduc

14、tingThecurrentoftheleakageinductor厶is/Lr=-/(0).ThepowerflowsfromV,sidetoV2side.Stage1/o,Zj:RefertoFig.2(b).At/0,Sa2isturnedoff.厶.C2andCa2begintoresonant,C2isdischargedandCa2ischarged.Stage2thr2：RefertoFig.2(c).AtfhthevoltageacrossC2attemptstoovershootthenegativerailD2isthereforeforwardbiased.Duringt

15、hisperiod,S2canbeturnedonatzerovoltageThevoltageacrossCa2isclampedatVCc.ThecurrentoftheleakageinductorLris2/12(a)Stage0before/oFig.1.ThenovelPSPZVSBBC(a)Maincircuit,(b)Keywaveformsin(heBoostmode,(c)KeywaveformsintheBuckmode(b)StageIRoJi(c)Stage2(/i,hQC,Gi*h3_cb也n:(d)Stage3|/2,01诙T-Gaaii1:c(C)stage4|

16、/5，川(0Stage5|h,/5|Fig.2.EquivalentcircuitsofswitchingstagesintheB)Lr,0uo,(2d-l)n(12FQd二l)7l(0-d7T)+0(兀一0)(2/j2)2ncoLr0u(2d-l)jrm(1)Fig.3showstherelationsbetweentheoutputpowerandphase-shiftangleunderPSandPSPcontrol.TheboldcurvesarcpowerversusV】underPSPcontrol.TheintersectioncurvesarepowerversusV】unde

17、rPScontrol.WhenV)andV2arcmatching(M=32V,V2=270V),thebothcurvesaresuperpositionunderPScontrolandPSPcontrol.B.CirculatingCurrentWhentransmittedpoweristhecurrentRMSof厶isFig.3.Curvesotlheoutputpowerversusthephase-shillangle.(pu=2(/IiV2/2n2)2，VI=22-32V)PScontrol時京ii15iSV1|列Rg.4.TheRMSvalueoffa.(Vj=22-32V

18、.V：=270V./匕：川=2PN=1.5kW,100kHz,/1.2pH)Fig.4showsthecomparingofthecurrentRMSofLrunderPScontrolandPSPcontrol.Inevidence,thecirculatingcurrentislessunderPSPcontrol.C.RangeforAchievingSoftSwitchingFromthesectionILitcanbeknownthatinordertoachieveZVSforallswitches,equation(5)shouldbesatisfiedinBoostmode5(

19、A)V-%2(A)v，沁2)/厶1(，2)(5)zLr(Z4)Also,equation(6)shouldbesatisfiedinBuckmode7厶r(3)0Thisconvertercansatisfy(5)or(6)wellfromnoloadtofullloadunderPSPcontrol.Inotherwords,comparedwiththePScontrol,thePSPcontrolcanexpandtheZVSningc.ControlStrategyhase.shin丁pfelCUT;CUR*Fig.6.ExperimentalwaveformsatVZ|=32Vand

20、V=22V(a)controlatV|=32V.(b)PSconlrolalVj=32V.(c)PSPcontrolatVzi=22V.(d)PScontrolatVj=22V.-Trigger-P阻ra8TbSYNCs3Thedecouplingcontrolofphase-shiftangle(panddutycycledisrealizedwithtwoindependenceclose-loopcircuits,asshowninFig.5Thephase-shiftangleclose-loopcircuitadoptsoneportvoltage(V2)regulatedandan

21、otherport(thebatteryport,VJcurrentregulatedtorealizetheenergybidirectionaltransmittedfreely.Thedutycycleclose-loopcircuitrealizesthematchingofV.andKdwhenV】isvariation.ExperimentalResultsAndDiscussionsInordertoverifytheoperationoftheproposedconvene匚a1.5kWprototypewasbuiltinlaboratory.Thebatteryvoltag

22、eofV】side:V)=22-32VDC.TheratedvoltageofV2side:V2=270VDC.Ratedpower:PN=15kW.Theturnsratioofthetransformer:n2：n=2A.Theleakageinductorofthetransformer:Lr=1.2pH.Theinductors:L=L2=15gH.Theclampingcapacitor:Cc=3iF.Thecapacitors:Ca=Cb=470gF.SwitchesS1andS2:APT20M11JFLL.SwitchesS3andS4:APT77N60JC3.SwitchesS

23、a1andSa2:APT20M16LFLL.t-f-Ttt7/jm*|2i4f/i/iv|Fig7.Galedrivesignal,thevollagcacrossthedrainandsource.andlhedraincurrentoftheswitchesatlullloadandVi=30VinBoostmode,(a)Si.(b)S3.(c)S小Fig.8.Gatedrivesignal,lhevoltageacrossthedrainandsourceandthedraincurrentoflheswitchesalfullloadandV：=3(X)VinBuckmode,(a)

24、Si.(b)S3.(c)St|.Switchingfrequency:fs=100kH乙Fig.6(a)and(b)showtheexperimentalwaveformsoftheleakageinductorcurrentLtheprimaryvoltage%，andthesecondaryvoltagevcdatV)=32VinBoostmodewith1.5kWoutputpowerunderPSPandPScontrolrespcctively.SincethevoltageV,andvoltageV2arcmatchinthiscase,themaximumcurrentofLru

25、nderPSPcontrolandPScontrolisthesameFig.6(c)and(d)showtheexperimentalwaveformsoftheleakageinductorcurrenti“,theprimaryvoltagevab,andthesecondaryvoltagevcdatV|=22VinBoostmodewith300WoutputpowerunderPSPcontrolandPScontrol.Inthiscase,voltageV,andvoltageV2arcnotmatched.Therefore,thecurrentstressof厶withPS

26、controlishigherthanthatofPSPcontrol.Fig.7(a),(b)and(c)showthegatedrivesignal,voltageacrossthedrainandsourceandthedraincurrentofShS3andSairespectively,atVj=30VinBoostmodewith1.5kWoutputpowerunderPSPcontrol.Fig.8(a),(b)and(c)showthegatedrivesignal,voltageacrossthedrainandsource,andthedraincurrentofShS

27、3andSahrespectively,atV2=3OOVand/i=-45AinBuckmodewith1.5kWoutputpowerunderPSPcontrol.Fig.7andFig.8illustratethatalltheswitchesrealizeZVS.Theexperimentalresultsarcinagreementwiththetheoreticalanalysiswell. #1.4244-0714-1.07/S20.00C2007IEEE. # 1.4244-0714-1.07/S20.00C2007IEEE. #J二】*_v.：(2wr7rf/vj-:-:1

28、7?/ne:(40/w/v|-Fig.9.WaveformoftheenergybidirectionalTransmitted.Fig.1()Conversioncllicicncy.(a)ThecHicicncyindillcrcntoutputpowerandVivoltageunderPSPconlrol.(b)ThecllicicncyinBoostmodeunderPSPcontrol.Fig.9showsthedynamicexperimentalwaveformsoftheenergybidirectionalconversionprocess,fromuptobottom,t

29、herearevoltagev2andcurrentWhenthevoltageonV2portishigherthanthereferencevalue,thebidirectionaldc-dcconverterchargesthebattery.WhenthevoltageonV2portdrops,thebatteryturnstodischargeandmaintainsthev2voltageas270VDCTheexperimentalresultsconvincedthatthenovelcontrolstrategycancontroltheenergyconversionf

30、reely.Therespondtimeofvoltagerebuildingis10msTherefore,thisconverterhasthehighsteadyanddynamicperformance.Fig.10(a)showstheoverallefficiencycurvesatdifferentloadandV)voltageunderPSPcontrol.Fig.10(b)showstheefficiencycurvesoftheconverterunderPSPcontrolandPScontrol.ItcanbeeasilyfindthatPSPcontrolhashi

31、gherefficiencythanPScontrolespeciallyinlowbatteryvoltageConclusionThispaperproposedannovelZVSbidirectionaldc-dcconverterwithPSplusPWMcontrol,whichhasthefollowingadvantages:TheconverteravoidsthevoltagespikewiththeuseofanactiveclampingbranchSal,Sa2andCc.ThePSplusPWMcontrolreducescirculatingcurrentandexpandstheZVSrangeThedecouplingcontrolrealizestheenergyconversionfreely,whichhasthehighsteadyanddynamicperformanceReferences11)FanghuaZhang.LanXiao,andYangguangYanBi-directionall