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iIntegratedEMI/ThermalDesignforSwitchingPowerSuppliesWeiZhangThesissubmittedtotheFacultyoftheVirginiaPolytechnicInstituteandStateUniversityinpartialfulfillmentoftherequirementsforthedegreeofMasterofScienceinElectricalEngineeringFredC.LeeDanY.ChenDushanBorojevichFebruary9,1998Blacksburg,VirginiaKeywords:EMI,Thermal,SwitchingpowersuppliesiiIntegratedEMI/ThermalDesignforSwitchingPowerSuppliesWeiZhang(ABSTRACT)ThisworkpresentsthemodelingandanalysisofEMIandthermalperformanceforswitchpowersupplybyusingtheCADtools.Themethodologyanddesignguidelinesaredeveloped.ByusingaboostPFCcircuitasanexample,anequivalentcircuitmodelisbuiltforEMInoisepredictionandanalysis.TheparasiticelementsofcircuitlayoutandcomponentsareextractedanalyticallyorbyusingCADtools.Basedonthemodel,circuitlayoutandmagneticcomponentdesignaremodifiedtominimizecircuitEMI.EMIfiltercanbedesignedatanearlystagewithoutprototypeimplementation.Inthesecondpart,thermalanalysesareconductedforthecircuitbyusingthesoftwareFlotherm,whichincludesthemechanismofconduction,convectionandradiation.Thermalmodelsarebuiltforthecomponents.Thermalperformanceofthecircuitandthetemperatureprofileofcomponentsarepredicted.Improvedthermalmanagementandwindingarrangementareinvestigatedtoreducetemperature.Inthethirdpart,severalcircuitlayoutsandinductordesignexamplesarecheckedfromboththeEMIandthermalpointofview.Insightfulinformationisobtained.AcknowledgementsiiiAcknowledgementsIwouldliketoexpressthedeepestandsinceregratitudeformyadvisorsDr.FredC.LeeandDr.DanY.Chen,fortheirguidanceandgreatsupportduringthework.TheextensiveknowledgeandinsightfuladviceofDr.Leehaveguidedmethoroughtheresearch.ThemanyhelpfulsuggestionsanddetaildiscussionswithDr.Chenenablemetofinishthework.Withoutthehelpfromthem,itisimpossibleformetostartandfinishthework.ImustalsothankmyMaster’scommitteememberDr.DushanBorojevich,forhisgreatsupportregardingtheresearch.Iamgratefulfortheexcellentfaculty,staffandstudentsatVirginiaPowerElectronicsCenterfortheirfriendshipandtechnicalhelp.Particularly,IwouldliketothankDr.MichaelT.Zhang,Dr.GlennR.Skuttfortheirinitiativeguidanceandhelpinthestudy.IwouldliketoexpressmyappreciationtoMr.LimingYe,Mr.WeiChen,etc.,fortheirfriendshipandsharingtheknowledgewithme.FinallyIwouldliketodedicatethethesistomydearparents,GuoweiZhangandSufangRen,fortheirloveandsupportintheseyears.Thegreatthankgoestomymotherforheraccompanyingmeandsacrificeduringthetimeforpreparingthethesis.ThisworkwassupportedunderPhilip’sFellowship,providedbyPhilip’sLaboratory,U.S.A.TableofContentsivTableofContentsChapter1.............................................................................................................................1Introduction.........................................................................................................................11.1.BackgroundandMotivation....................................................................................11.2.Approach..................................................................................................................21.3.ThesisOutline...........................................................................................................3ChapterTwo........................................................................................................................5EMIPredictionandMinimization......................................................................................52.1.ParasiticParameterExtractionandModeling..........................................................82.1.1.LayoutInductanceExtraction............................................................................92.1.2.ParasiticCapacitanceCalculation....................................................................132.1.3.PowerDeviceModels......................................................................................132.1.4.PassiveComponentsModel...........................................................................152.1.5.MagneticComponentsModel.........................................................................192.1.5.1.AnalyticalEstimationofWindingCapacitance.....................................192.1.5.2.LabMeasurementofParasiticC............................................................242.2.ConductedEMIPredictionandVerification..........................................................252.2.1.LISNModel...................................................................................................252.2.2.NoiseSpectrumCalculation...........................................................................252.2.3.ExperimentalVerification..............................................................................272.3.ConductedNoiseAnalysis.....................................................................................292.3.1.Differential-modeNoise.................................................................................292.3.2.Common-modeNoise.....................................................................................302.4.Nois