13-Permanent-Magnet-Motor

PermanentMagnetSynchronousMotor(PMSM)IntroductionPermanentMagnet(PM)MotorCharacterizedbypermanentmagnetsonrotorKnownforitssimplicityandlowmaintenanceNocopperlossonrotorHighefficiencyExplodedViewofaPMMotorJ.R.HendershotandT.J.E.Miller,DesignofBrushlessPermanentMagnetMachines2ndEdition,p.44,MotorDesignBooksLLC,2010.InnerRotorPossibilities(1)surfaceradialmagnetsurfaceparallelmagnetbreadloafmagnetringmagnetInnerRotorPossibilities(2)(e)IPMrotorwith2magnets/poleinaV-shapedfluxconcentratingarrangementMS-TECHJapanToyotaPriusRotorFluxDistributionofIPMsToyotaPriusHybridElectricVehicle(HEV)1.Fourcylindercombustionengine;2.Generator/starter;3.ElectricMotor;4.Powersplitdevice(PSD)23J.F.Gieras,PermanentMagnetMotorTechnology-DesignandApplications,3rdEdition,p.282,CRCPress,2010.J.R.HendershotandT.J.E.Miller,DesignofBrushlessPermanentMagnetMachines2ndEdition,p.34,MotorDesignBooksLLC,2010.SegmentedMagnetsinLargePMRotorJ.R.HendershotandT.J.E.Miller,DesignofBrushlessPermanentMagnetMachines2ndEdition,p.94&602,MotorDesignBooksLLC,2010.RotorSkewsteppedmagnetMagnetizationProfile(1)parallelmagnetizationradialmagnetizationradialsinemagnetizationsineangleorsinedirectionmagnetizationmostpopularMagnetizationProfile(2)Fluxofa8polemachineatnoloadradialmagnetizationairgapfluxdensityprofileversusangle8dd4590135180MagnetizationProfile(3)radialmagnetizationparallelmagnetizationFluxin2PoleMachineatnoload2d2dddMagnetizationProfile(4),grotorBmBmB22PMPM2PM22PMde2PMradialmagnetizationparallelmagnetization,grotorBmB22PMPM2PM22PMde2PMPMembrace:PMembelectricalanglePMHalbachArray(1)R.Krishnan,PermanentMagnetSynchronousandBrushlessDCMotorDrives,p.25-30,CRCpress,2010.HalbachArray(2)FEAHalbachArray(3)AirgapFluxDensityRotorisoutsidePermanentMagnetSynchronousMotor(PMSM)DesignPart1–GeneralConsiderationsStatorVolumeandSize02VTlDTheunitforDandLisinch.304~5in/(ftlb)for10hpormore(watercooled)VTypically308~9in/(ftlb)for10hporless(aircooled)VIfwedesignD=L,wehavethestatorbore(inner)diameterestimated310)(TVDestimatedWecanpickupDclosetoDestimated.moutPTStatorCoreDesign,=(1)gpkcorecoreccDBBdlPd,(2)sgpktoothtoothssBBtlt,0()toothgaeiaegpkslBrdBl,/0/2,0,()2cos()2coregapperhalfpolepitchPgaisagpkaeaegpklBrdDlBdPDlBPTake0.5,0.8sscoretoothtBBPDdc6.1EffectofPoleNumberonYokeFluxDensityJ.R.HendershotandT.J.E.Miller,DesignofBrushlessPermanentMagnetMachines2ndEdition,p.106,MotorDesignBooksLLC,2010.FiniteElementAnalysiswiththesamedcNumberofTurnsperCoilpkgaepkgaeratedNfNfV,,,ˆ44.4ˆ2PDlBpkgpk,21.1/ˆawaNkNsdpwkkkkwhereDlBqkfCVNpkgweratedc,,221.1NaisthenumberofseriesturnsperphaseofarmaturewindingCisthenumberofparallelcircuitsofarmaturewindingCPqNNca/ConsiderleakagefluxStatorSlotDesignSDs37ssstdt0.40.6ssst0(0.1~0.5)ssbbGeneralConsiderationsdsts0sb0sd1sdDefinesssbt0(0.1~0.5)ssdb1(0.1~0.5)ssdbStatorConductorSizeStatorcurrentdensityaratedacoppersSCIJ/,,whereSaisstator(armature)conductorcrosssectionareaandcanbedeterminedfromtheaboveformulatogetherwith:2,2A/cm800400A/cm:cooled-AircoppersJcoppersratedaaJCIS,,/PermanentMagnetsSamarianCobalt(SmCo)Operatingtemperatureofupto350ºC2ndstrongestrareearthmagnetNeodymiumIronBoron(NdFeB)Operatingtemperatureofupto150ºCStrongestrareearthmagnetFromYeadon–HandbookofSmallElectricMotorsPermanentMagnetPropertiesRotorPeripheralSpeedThemaximumallowableperipheralspeedoftherotorisacentralconsiderationinmachinedesign.Withpresent-daysteelalloys,rotorperipheralspeedsof50,000ft/min(orabout250m/s)representthedesignlimit.1ft/min=0.0051m/sMotorLosses(1)CopperlossTypicalStraylossesElectricalphenomenonsuchasskinandproximityeffectRIPCu2MotorLosses(2)Core(Iron)LossHysteresislossEddyCurrentlossMechanicallossWindagelossFrictionloss2/32)()(BfBffBPecnhIronFiniteElementAnalysisFundamentalharmonicJ.R.HendershotandT.J.E.Miller,DesignofBrushlessPermanentMagnetMachines2ndEdition,p.174-175,MotorDesignBooksLLC,2010.Part2–SurfaceMountRoundRotorMulti-PolePMMotorDesignMagneticCircuitAnalysisForamulti-polesurfacemountrotormdPolesaDD220gmmHgHd00gmmgBHdg0mmlmmgdBkAgHAgggBAmmmBAglmk:LeakageCoefficientlkWorkingPointforPermanentMagnetics(1)B0H0cHrB)(ccrHHHBBHHHHBBHccr)(max()Toget(BH)0,22rcmmBHBHBHH0mRHmRBMaximumEnergyPointWorkingPointforPermanentMagnetics(2)LoadLine:00gmmmlmcmAdBHgkAPH11.2rmPciscalledpermeancecoefficient0//gggmmmcmlmlmmgmAAgBdPHgkAkAdRRPPDefine:(1)mmrmmcBBHH0.60.9mTypicallypickup:0rrmcBH01mmcrmmmBPHAirgapMagneticFieldfromPMRotor/2/2/2/22cos()()cos()2sin42PMPMPMPMrhmaeaemaeaePMmBBhdBhdhBh,1,3,5...cos()cos()2grotorRhhRhrhderhdBBPBBhBhsin2PMphkhpitchfactorforthehthharmonic,grotorBmBmB22PMPM2PM22PMde2PM2dedP2PMPMembrace:PMembelectricalanglePhasorDiagramVAEASjXIfull-loadpulloutTypically,designcos1atfull-loadforPMSM.Needtospecifytorqueangle,ifsin1/3(=19.47),T(1/3).T,,,,,,cos0.94si