双向DC-DC变换器在电动汽车中的应用

UPTECF10013Examensarbete30hpFebruari2010DesignandconstructionofabidirectionalDCDCconverterforanEVapplicationMagnusHedlundTeknisk-naturvetenskapligfakultetUTH-enhetenBesöksadress:ÅngströmlaboratorietLägerhyddsvägen1Hus4,Plan0Postadress:Box53675121UppsalaTelefon:018–4713003Telefax:018–4713000Hemsida:(suchasforPIandstatepredictionmethods).Aboostcontrolphilosophywaspresented,basedonacurrentsourceapproximation.Thecontrolwasfoundtobestablewithoutsteady-stateerrorswhenthevarianceoftheinput/outputdynamicswashigh.ThetargetapplicationfortheDCDCConverterisanEV(ElectricVehicle)withaflywheeldriveline,whichputsadditionalrequirementsoftheconverter.Amongthesearecurrentandvoltagecontrol,bidirectionality,andabroadinputvoltagerange.SimulationswereperformedinSimulinkpriortophysicalimplementation,provingfunctionalityoftheproposedcontrolsystem.ThephysicalimplementationofthecontrolwasdoneonadigitalsignalprocessorwithcodecompiledfromC.Amedianfilterwasdesignedtoincreasemeasurementefficiencyforthecurrentsensorswhichhadshot-likenoisedistortions.ISSN:1401-5757,UPTECF10013Examinator:TomasNybergÄmnesgranskare:HansBernhoffHandledare:JanaínaGonçalvesdeOliveiraContents1Introduction12Theory42.1SwitchedConverters......................................42.1.1IntroductiontoDCDCConverters..........................42.1.2BuckandBoostCircuits................................52.1.3FourQuadrantChopper................................52.2ControlDesign.........................................72.2.1Introduction......................................72.2.2Systeminput/outputdynamics............................72.2.3SlidingModeControl.................................83Modelling103.1DynamicsofBuckConverter.................................103.1.1Stateequations.....................................103.1.2PhaseportraitsofBuckConverter..........................103.1.3ControlIdea......................................113.2DynamicsofBoostConverter.................................123.2.1Stateequations.....................................123.2.2PhaseportraitsofBoostConverter..........................133.2.3Problemswithcontrolidea..............................143.3Dynamicsof4QuadrantConverter..............................143.3.1BuckMode.......................................153.3.2BoostMode.......................................153.3.3QuadrantTransitions.................................173.3.4CurrentandVoltageControl.............................174Simulations184.1BuckConverter.........................................184.2BoostConverter........................................194.34QuadrantConverter.....................................205Implementation215.1MicroprocessorCode......................................225.2CurrentSensorFiltering....................................236ExperimentalResults256.1Transitionfrombucktoboost.................................256.2Transitionfromboosttobuck.................................256.3ChangeofCurrentDirection.................................266.4Fastchangesofoperatingquadrants.............................266.5MedianFilterAccuracy....................................277DiscussionandConclusion28References29AAppendix30A.1LinearControl-OpenControl&PID............................30A.2SimulinkBlockDiagrams...................................32A.2.1BuckConverterModelwithconstantdutyratio...................32A.2.2BuckConverterModelwithSlidingModeControl.................33A.2.3BoostModelwithconstantdutyratio........................33A.2.44QCModelwithBuckControl............................34A.2.54QCBuckControl1DModel.............................35A.2.64QCBuckControl2DModel.............................35A.2.74QCBoostControlModel...............................36A.34QCinbuckmodecomparedwithBuckCircuit.......................37A.4PartsList............................................38A.5Hardwaredrawing.......................................39A.6BuckStateEquations.....................................40A.7BoostStateEquations.....................................40BProcessorCode41ListofFigures1USUrbanDrivecycle......................................12ApproximatepowerandenergyratingsofEnergyStorages.................23Simulationoftheenergystoredintheflywheel.......................24Flywheeldriveline.......................................35ADCDCConverterModel...................................46DCDCConverterinthelowvoltagesideofaflywheelpowersystem............47BuckConverter.........................................58BoostConverter........................................594QuadrantConverter.....................................610Input/OutputDynamics....................................711B