LLC串联谐振全桥DCDC变换器的研究

华中科技大学硕士学位论文LLC串联谐振全桥DC/DC变换器的研究姓名：宫力申请学位级别：硕士专业：电力电子与电力传动指导教师：李晓帆20060428IDC/DCPWMZVSDC/DCZVSZVSLLCDC/DCPWMZVSDC/DCLLCDC/DCLLCDC/DCZVS500wIIAbstractInDC/DCconverterapplications,highfrequency,highpowerdensityandhighefficiencyisthedevelopmenttrend.Traditionalhard-switchedconvertersrestrictthedevelopmentofDC/DCconverter.Phase-shiftFullBridgePWMZVSDC/DCconverterhasbeenwidelyusedowingtoitsZVSconditionofmainswitches.Butitstillhassomedisadvantages,forexample:lagging-armswitchesishardtoachieveZVSinlightloadconditions;rectifierdiodehaveunavoidablerecoveryproblemsandtheynotonlycausegreatsecondaryloss,butalsoincreasethevoltagestressoftherectifierdiodes;convertercanachievehighefficiencyinlowinputDCvoltageconditionsbutlowefficiencyinhighinputDCvoltageconditions,thiskindofefficiencycharacteristicrestrictsitsapplicationsonhighinputDCvoltageoccasionsandhigh-qualityconverterswhichhavehold-uptimerequirements.Fortunately,asonefocusinDC/DCconvertersresearchfieldsnowadays,LLCseriesresonantFullBridgeDC/DCconvertercansolvetheseproblemssuccessfully.Butowingtoitscomplexitycausedbymulti-resonantprocess,it’shardtoanalyze,designandcontrol.SoLLCseriesresonantFullBridgeDC/DCconverterhasbiggishresearchvalue.Inthispaper,LLCseriesresonantFullBridgeDC/DCconverterisanalyzedindetail.Basedonthefundermentalelementsimplificationmethod,themathematicsmodeloftheconverterisobtained,theconditionstoachieveZVSaregiven.SteadyworkingregionofLLCseriesresonantFullBridgeDC/DCisconfirmed,therelationsbetweeninputandoutputvoltagedependingonswitchingfrequencyandloadconditionsaregiven.Simulationresultsprovethecorrectnessofthetheory.Inordertodesigncontroller,small-signalmodeloftheconvertermustbegiven.Inthispaper,thesmall-signalmodelofLLCseriesresonantFullBridgeDC/DCconvertersisdeducedusingExtendedDesicribingFunctionMethod.Also,stabilityoftheconverterisanalysedandcontrollerisdesignedtomeettherequirmentsofdynamicprocess.Simulationresultsprovethecorrectnessoftheory.Basedontheoryanalysis,a500wprototypecircuitisdesigned,andthedesignstepsisgiven.Theexperimentalresultsprovetheefficiencyoftheconverter.Keywords:DC/DCconverterSoft-switchingSeries-resonantSmall-signalmodel_____111.1[1][2]200040%21[1]1.1.1[1][2](1)AC/DCAC/DCAC/DC2(2)DC/ACUPS(3)AC/AC(AC/DC/AC)--IGBTPWM(4)DC/DC(AC/DC/DC)DC/DCNemicLambdaRM200300kHz27w/cm3MOSFET90%(5)1.2DC/DC[3][4][5][6][7](1)MOSFETIGBT400kHz(AC/DC)1MHz(DC/DC)MOSFET(3V)(2)PWM//80-85%703ZVSPWMZVSPWM/ZCSPWMZVSPWMZVTPWM/ZCTPWMZVSZCSPWM(3)(PFC)PFCPFCPFCPFCAC-DCAPFCAC/DCAC/DC(UPS)0.6580APFC0.950.99APFCDC/DCAPFCPWM(4)(5)(EMC)EMIEMC(6)(7)4DC/DC(8)()1.3[3](1),(2)di/dtdv/dt(EMI)1.3.1DC/ACDC/AC[6]DC/DC1986D.M.DivanRDCLI(RPI)PWM51.3.2DC/DC,RLC[1][3][6](1)Resonantconverters(2)QRCsMRCs(3)PWMZeroswitchingPWMconvertersPWMPWMQRCsPWMQRCs1/101/5(4)PWMZerotransitionconvertersPWMPWM.PWM61.4LLCDC/DCLLC1).LLCDC/DCPWMZVSDC/DCMOSFETIGBTLLCDC/DCLLCDC/DC2).LLCDC/DCDC/DCLLCDC/DC3).LLCDC/DC4).72LLCDC/DCZVSPWM[8](Hold-uptime)LLCPWMZVSMOSFETMOSFETLLCLLC2.1PWMZVS2.1.1PWMZVSPWMZVS2.1PWMT1T2T3T4C1C4T1T4LrT1T2T4T3D5D6LfCfLfIf[1][3][9]D6D5T1D1C1T2D2C2T3D3C3T4D4C4VinLrRLLfCfABipIfK:1Vo2.1PWMZVSDC/DCPWMZVS2.2ttdip81[t0-t1]t0T1ipT1C1C2C1C2LrLfLfipC1C2Vint1C2T2D2T2T1T2iD5iD6ipVABVgsViniD5iD6Vrt0OttdT1T4T3T4t1t2t3t4t5t6t7t8t9t10t11ttttt2.22[t1-t2]t1T2T4VAB=0,ipT4,D2LripD5IfD2t01=t1t0td,T2T2T2D23[t2-t3]t2T4ipC3C4C3Vc3VinC4Vc4T4D6If9D5D6D5,D64[t3t4]t3C4VinC3D3Vc3=0t23=t3-t2tdT3T3T3D35[t4t5]t4ipID6IfD5D66[t5t6]t5ipIf/K(K)D5D6IfD6t6T22.1.2ZVSPWM1).ZVSZVSZVST2t01ip(ip=If)L=Lr+K2LfZVST3t23ip(ipIf/K)D5D6LrZVSZVS[1][3]ZVS222412≥rinLICV(2-1)I2t2I2ZVS2).[1]PWMZVSDC/DCLrLfVABD5(D6)D5D6(t2t5t810t11)D5D6Vr2.3D5D6VpK:1LfCfILfipiD5iD6IstrrIrmILfiD5vABVDVD5ttt2Vrot1t2t5VrmVo2.33).VinVin[3]PWMZVSDC/DC2.2MOSFETIGBTIGBTMOSFETMOSFETIGBT11MOSFETIGBTMOSFETLLCMOSFETIGBT2.4IGBTMOSFETP[10][11]MOSFETIGBTMOSFETIGBT(2-2)CrssCrssigsgdodsgdrgdCCCCCCCC=+=+=igegcocegcrgcCCCCCCCC=+=+=(2-2)GDSCgdCgsCdsCECgcCgeCceG2.4MOSFETIGBTMOSFETCrssMOSFETMOSCgdIGBTMOSFETPPNPNCPN(CBCD)IGBTCgcCPNCrssMOSFETIXYSMOSFETIGBT[10]2.1(Vds=Vce=25VVgs=Vge=0Vfs=1MHz)2.1MOSFETIGBTVdss(Vces)Ciss(PF)Coss(PF)Crss(PF)MOSFETIXFN44N60600V89001000330IGBTIXDP20N60B600V8008550MOSFETIGBT10IGBTNP()12P+N-PMOSNN-()MOSFETIGBTNN,ic[11]MOSFETIGBTMOSFETIGBT1)MOSFET[12]IGBTMOSFET2)MOSFETMOSFET[10]IGBT()MOSFETIGBTMOSFETZVSMOSFETIGBTZCS2.3LLCLLCDC/DC2.5MOST1-T4T1T4T2T350%T1(T4)T2(T3)D1-D4MOSLrLmCrD5-D6Cf[13][14][15]2.1LLCDC/DCPWMZVSDC/DC1).CrCr13VinT1T2T3T4LrCrLmCfRLD1D3D2D4D6D5Vo2.5LLCDC/DC2).TLmLLC3)LfLmLf2.3.1LLCLLC2.6(Tswsw0)LrCrRVsiVstVin-VinoTsTs/2ZiLeCrReVsiZiLm2.6LLCLeRe2222smersmRwLLLRwL=++(2-3)22222smesmRwLRRwL=+(2-4)141,3,5,...41()sin()inssnVVtnwtnπ∞==∑(2-5)n1()()insesesrZjnwRjnwLnwC=+−(2-6)2222202220()1(1)sinsesnQwwZjnwRwnw=+−(2-7)01erwLC=(2-8)0reeeZwLQRR==(2-9)n|in|/|i1|222220222041(1)sninninsesVViZnQwwnRwnwπ==+−(2-10)22220220222212022201(1)1(1)snsssQwwiwwinQwwnwnw+−=+−(2-11)|in|/|i1|Qws/w02.72.7ws(ws/w0=0.5)3Q57Qws(ws/w0=0.8)(ws/w0=1)w0(ws/w0=1.2),QQwsw0|in|/|i1|ws/w0ws/w0=0.8Q2.535710%3.2%1.8%ws/w0=1Q2.53575%1.8%0.9%Qwsw015[8][16]a)ws