汽车空调系统

InternationalJournalofAutomotiveTechnology,Vol.11,No.2,pp.277−282(2010)DOI10.1007/s12239−010−0035−zCopyright©2010KSAE1229−9138/2010/051−17277SIMPLEDESIGNAPPROACHFORIMPROVINGCHARACTERISTICSOFINTERIORPERMANENTMAGNETSYNCHRONOUSMOTORSFORELECTRICAIR-CONDITIONERSYSTEMSINHEVS.I.KIM,G.H.LEE,J.J.LEEandJ.P.HONG*DepartmentofAutomotiveEngineering,HanyangUniversity,Seoul133-791,Korea(Received18February2009;Revised20July2009)ABSTRACT−Inthispaper,asimpledesignmethodforimprovingtheperformanceofaninteriorpermanentmagnetsynchronousmotor(IPMSM),fordrivingtheair-conditioningcompressorusedinhybridelectricvehicles,ispresented.TherearemanydesignmethodsthatoptimizetheIPMSM.Eachmethoddealswithavarietyofdesignfactors,suchasslotopening,polearc,androtorshape.However,asthenumberofdesignvariablesincreases,alotofmodelingandanalysistimeisneededinordertoimprovethecharacteristicsofanIPMSM.Thispaperdemonstratesthattheoptimizationofadouble-layerIPMSM,satisfyingthegivendesignconditions,ispossiblewithonlyafluxbarriershapedesign.Then,responsesurfacemethodologyisappliedastheoptimizationmethod,andthevalidityofthedesignapproachisverifiedbycomparisonwithtestresults.KEYWORDS:Air-conditioningcompressor,IPMSM,Optimization,Responsesurfacemethodology1.INTRODUCTIONIdlingstopsystemstoreducefuelconsumptionareofinterestfordevelopersofhybridelectricvehicles(HEV).Inordertoadapttotheidlingstopsystem,theautomobileair-conditionermustcontinuetoworkevenwhiletheengineisstopped.Assuch,conventionalengine-drivencompressorsaregraduallybeingreplacedwithelectricmotor-drivenmodels.Themotorsfordrivingair-conditioningcompressorsinHEVsmustbeminiature,lightweight,andhighlyeffici-ent.Interiorpermanentmagnetsynchronousmotors(IPMSMs)arewellsuitedtothesedesignrequirementsduetotheirhighpowerdensity,highefficiencyandwidespeedregion(Murakamietal.,2001).However,IPMSMshavelimitationsrelatedtotorquecharacteristics.Torquerippleandcoggingtorquearerelativelylargecomparedwithasurfaceper-manentmagnetsynchronousmotor.Theselimitationsaremainlytheresultofdiscontinuousreluctancevariationbet-weentherotorandstator(Kioumarusietal.,2006;Bianchietal.,2006;Islametal.,2005;Sanadaetal.,2004).Especially,becauseofd-axiscurrenttoutilizereluctancetorqueandincreasethemotorspeed,theback-electro-motiveforce(back-EMF)oftheIPMSMoperatedinwidespeedrangecontainsmanyharmonics,andthetorqueripplerisesgreatlywhendrivenbyasinusoidalcurrent(Leeetal.,2008).Therefore,itisnecessarytooptimizetheshapeoftheIPMSMinordertoimprovetorqueperfor-mance.Thisoptimizationisverycomplexanddifficultduetomanydesignfactorsandtheinteractionsbetweenthem.Unfortunately,thereareveryfewtechnicalpapersthatdis-cusshowvariationsofdesignvariableseffecttorqueripple,coggingtorqueandharmonicsofback-EMF.Thesmallnumberofpapersthathaveappeared(Kioumarusietal.,2006;Sanadaetal.,2004)offeradesignmethodformiti-gatingoveralltorquepulsationundervariousloadcondi-tions.Thegoalofthispaperistopresentarelativelysimpleandfeasibledesignapproachthatwillfacilitateanimprove-mentsintheabovementionedcharacteristicswithoutanysacrificetootherperformancecharacteristicsofthedouble-layerIPMSM.Themethodemploystheresponsesurfacemethod(RSM)andconsidersthefluxbarrierastheonlydesignfactor.RSMiswellsuitedformakingempiricalmodelsthatrelatetheperformanceofamotortothedesignparameters.Withtheseempiricalmodels,theobjectivefunctionswithrestraintsareeasilycreatedandalotofcomputationaltimecanbesaved(Jeonetal.,2006;Qinghuaetal.,2004).Furthermore,anobtainedresponsesurface*Correspondingauthor.e-mail:[e-mail],G.H.LEE,J.J.LEEandJ.P.HONGsuppliesadesignerwithadescriptionofsystemresponsesbasedonthebehaviorofdesignparameterswithinadesignspace.Conventionaloptimizationmethodscannotprovidethis.Intheend,theutilityofthemethodforthefluxbarriershapedesignisverifiedbytestresults.2.CHARACTERISTICSOFINITIALMODELFigure1showstheinitialconfigurationofthedouble-layerIPMSMdesignedfordrivingthecompressorofaHEV.Theconstantpowerspeedrange(CPSR)oftheinitialmodelis3500rpmto7500rpm.ThemaindimensionsandspecificationsarelistedinTable1.Thecharacteristicsofthemodelareestimatedbyfiniteelementanalysis(FEA)andthevoltageandtorqueequation;mechanicalandironlossareignored.Theequationsinnormaloperationareexpressedind-qcoordinatesasfollows(ChinandSoulard,2003):(1)(2)where,idandiqarecomponentsofarmaturecurrent,vd,vqarecomponentsofterminalvoltageψaψf;ψf:isthemaximumfluxlinkageofthepermanentmagnet,Raisthearmaturewindingresistance,Ld,Lqareinductancealongd-,andq-axis,p=d/dt,andPnisthenumberofpolepairs.Atthebaseandmaximumspeed,inputarmaturecurrentandcurrentangle(β)arerequiredtoestimatetorqueripplebyFEA(Kioumarusietal.,2006;Sanadaetal.,2004).Togetthesevalues,LdandLqshouldbecomputedaccordingtothechangeofarmaturecurrentandβ.Inthispaper,theyareobtainedbyFEAcubicsplineinterpolationand(3).LdandLqasafunctionofcurrentandβareshowninFigure2.In(3),ψaandψoarefundamentalcomponentscalculatedbyFourieranalysis.Thesteady-statephasordiagramfortheIPMSMisshowninFigure3(Morimotoetal.,1990).(3)whe