关闭

关闭

关闭

封号提示

内容

首页 A New Control Technique for Achieving Wide Cons…

A New Control Technique for Achieving Wide Constant Power Speed.pdf

A New Control Technique for Ach…

上传者: 理性遇见非理性 2014-03-30 评分 0 0 0 0 0 0 暂无简介 简介 举报

简介:本文档为《A New Control Technique for Achieving Wide Constant Power Speedpdf》,可适用于IT/计算机领域,主题内容包含ANewControlTechniqueforAchievingWideConstantPowerSpeedOperationwithanInter符等。

ANewControlTechniqueforAchievingWideConstantPowerSpeedOperationwithanInteriorPMAlternatorMachineJacksonWaiThomasMJahnsUniversityofWisconsinMadisonEngineeringDriveMadison,WIPh:Fax:EMail:waijcaewisceduUniversityofWisconsinMadisonEngineeringDriveMadison,WIPh:Fax:EMail:jahnsengrwisceduAbstractAnewfluxweakeningcontrolalgorithmispresentedforachievingwideconstantpoweroperationwithaninteriorpermanentmagnet(IPM)synchronousmachineoperatingasanalternatorThealgorithmisdesignedtoinitiatefluxweakeningonlywhennecessarybyrecognizingthethresholdconditionsforcurrentregulatorsaturation,makingthealgorithminherentlyadaptivetochangesintheinverterbusvoltageAkWVautomotiveintegratedstarteralternator(ISA)usingadirectdriveIPMmachineservesasthetargetapplicationforthisdevelopmentSimulationresultsshowthatthenewalgorithmiscapableofdeliveringverygoodstaticanddynamicbusregulationcharacteristicsovera:engineoperatingspeedrangeTestsarepresentlyunderwaytoconfirmtheseperformancepredictionsusingaprototypeIPMstarteralternatorsystemKeywords:Permanentmagnetmachines,ACmotordrives,roadvehiclepowersystems,powercontrol,synchronousgeneratorsIINTRODUCTIONWithproperdesign,aninteriorpermanentmagnet(IPM)synchronousmachinecanachieveconstantpoweroperationoverawidespeedrangeinboththemotoringandgeneratingregimesAsaresult,IPMmachinesareattractingincreasingattentionforavarietyofapplicationsrangingfromelectricvehiclepropulsiontomachinetoolsWhilethedesignofanIPMmachineforextendedspeedoperationposesseveraltechnicalchallenges,thesuccessofthecompletedrivesystemdependsontheavailabilityofanappropriatecontrolalgorithmthatcanextractthefullperformancecapabilitiesfromthemachineInparticular,specialfluxweakeningcontroltechniquesarenecessarytoachieveconstantpoweroperationoverawidespeedrangePreviousworkreportedintheliteraturehasgenerallyfocusedonextendedspeedrangeapplicationsfortheIPMmachineoperatingasamotorThispaperpresentsanewcontrolalgorithmdesignedtoextractnearconstantpowerfromanIPMmachineoverawidespeedrangewhenitisoperatingasanalternatorTheapplicationthathasmotivatedthisworkisadirectdriveintegratedstarteralternator(ISA)foranautomotivevehicleThedevelopmentofmanynewelectricallySArotoractsasflywheelTorqueconverterinsiderotorhubFlywheel,alternator,starter,pulley,possiblyabelteliminatedNewPartsEliminatedPartsFigIntegratedstarteralternator(ISA)configurationpoweredaccessoriescombinedwithwideinterestinmildhybridconceptsusingelectricmachinesforlowspeedaccelerationhasdrawnsignificantattentiontoISAsystemsAsillustratedinFig,thenewISAreplacestheconventionalengineflywheelandisdrivendirectlybytheenginecrankshaftwithoutgearingThemachineisdesignedtooperateasboththeenginestarterandalternator,replacingthetwoseparatemachinesthatperformthesefunctionsinconventionalvehicles,alongwiththeirassociatedpulleys,belts,andgearsPerformancespecificationsdevelopedinconsultationwithseveralautomotivemanufacturerscallfortheISAtosupplyNmofstartingtorqueatlowspeedsInaddition,theISAmustdeliverVpowertotheautomotiveaccessoriesovera:speedrangeextendingfromKWatrpmtoKWatrpmItisthislatterrequirementthatmotivatedselectionoftheIPMmachineforfurtherdevelopmentasanattractivecandidateforthisapplicationSignificantprogresshasbeenmadetowardsdevelopmentofanIPMmachinethatiscapableofmeetingthesechallengingapplicationrequirementsThisefforthasculminatedinconstructionofaprototypeversionofapoleIPMmachinedesignedforthisdirectdriveISAapplicationFigureshowsthestatorandrotorofthismachine,illustratingitsuseoftwomagnetcavitiesperpolewithsaturatingmagneticbridgesthatlinktheironpolepiecesintounitaryrotorlaminationsX$(C)IEEEFigRotorandstatorassembliesofprototypekWIPMmachineforISAapplicationIICONTROLTECHNIQUEPRESENTATIONAIPMMachineOperatingEnvelopeTheprinciplesforachievingwideconstantpoweroperationusingIPMsynchronousmachineshavebeenestablishedinthetechnicalliterature,ThemachineequationsgoverningthedynamicoperationoftheIPMmachineintherotordqreferenceframearesummarizedbelowNotethatthedaxisisalignedwiththerotorpermanentmagnetfluxvd=rsidpldswrlqs()vq=rsiqplqswrlds()lds=Ldsidfpm()lqs=Lqsiq()whereidandiqarethedandqaxisstatorcurrentsAvdandvqarethedandqaxisstatorvoltagesVldsandlqsarethedandqaxisstatorfluxlinkagesWbLdsandLqsarethedandqaxisstatorinductancesH(NotethatLqs>LdsinanIPMmachine)fpmisthedaxispermanentmagnetfluxlinkageWbwristherotorrotationfrequencyelecradsMagneticsaturationhasasignificantimpactontheoperatingcharacteristicsofanIPMmachineExperiencewiththeautomotiveISAmachine,hasindicatedthatsaturationcanbemodeledquiteaccuratelybymakingLqsafunctionoftheqaxisstatorcurrentiqwhiletreatingLdsasaconstantCrosscouplingsaturationeffectsbetweentheqanddaxesarenotsignificantinthismachineandarenotincludedinthismodelEquations()and()canberewrittenusing()and()pluschaindifferentiationtoreflectthefactthatLqsisafunctionofiq:vd=rsidLdspidwrLqsiqs()vq=rsiqLqs'piqwr(Ldsidfpm)()whereLqs'=qqsiLiqLqs()Previouswork,hasdemonstratedthevalueofthedqcurrentplaneforevaluatingtheextendedspeedoperatingcharacteristicsofIPMmachinesMorespecifically,suchplotsprovideameansofvisuallydepictingtheconstraintsimposedbytheinvertervoltageandcurrentlimitsandtheirinteractionsFigurepresentsthedqcurrentplaneplotfortheISAmachinedescribedabovewhoseelectricalparametersareprovidedintheAppendixTheAppendixincludesanumericalexpressionforLqsasafunctioniqthathasbeenfittomachine'sinductancecharacteristicsThecurrentlimitmanifestsitselfinFigasacircleofamplitudeA(peak)centeredattheorigin,whilethevoltagelimittakestheformofafamilyofnestedellipsesallcenteredattheIPMmachine'scharacteristiccurrentvalue,fpmLdsTheradiioftheellipsesvaryinverselywiththerotorspeedTheseellipsesaredistortedinthevertical(iq)directionbecauseofLqssaturationeffects,andtheirlongestdiametersexhibitanoticeablecounterclockwisetiltfromthehorizontal(id)axisbecauseofstatorresistanceeffectsAtanygivenspeed,theIPMmachinecanoperateatanycombinationofiqandidvaluesthatfallswithintheoverlappingareaofthecurrentlimitcircleandthevoltagelimitellipseassociatedwiththatspeedidAiqACurrentLimitCircleImaxVoltageEllipsesMaxTAwithoutsaturationMaxTAwithLqssaturationeffectMotoringGeneratingffPMLdswwrincreasingGeneratingModeEnvelopeTrajectoryFigPlotofidiqcurrentplaneforthekWIPMmachineshowingcurrentlimitcircle,voltagelimitellipses,andcurrentvectortrajectoriesFigureidentifiesthemaximumtorqueperAmpcurrentvectortrajectoryfortheISAmachineinthesecondquadrantmotoringregimeforstartingoperation,withandwithouttheeffectsofmagneticsaturationThetrajectorywithoutsaturationformsananglewiththenegative–idaxisthatexceedsdegrees,whiletheangleofthecorrespondingtrajectorywithsaturationislessthandegreesDuringgeneratingoperationoftheIPMmachineatelevatedspeed,themaximumoutputpowerpointfollowstheperipheryofthecurrentlimitcircletowardsthenegativeidaxisasindicatedinFigThismotionisforcedbytheincreasingspeedthatprogressivelyshrinksthevoltagelimitellipse,preventingthemachinefromoperatinginthevicinityofthemaximumtorqueperAmptrajectory(forgenerating)identifiedbyadashedlineinFigTheamplitudeoftheISAmachine'scharacteristiccurrent,fpmLds(=A)islessthantheinvertercurrentlimit(A)ThismayseemsurprisingsinceoptimumextendedspeedoperationoccurswhenthevalueoffpmLdsequalstheinvertercurrentlimitHowever,theotherISAsystemspecifications,includingalimitonthemachine’smaximumbackemfamplitude,resultinthislowervalueofcharacteristiccurrentGiventhissituation,themaximumgeneratingoutputpowertrajectoryeventuallyseparatesfromthecurrentlimitcircleasthespeedincreases,followingatrajectorythatleadstothefpmLdscharacteristiccurrentpointonthenegativeidaxisatinfinitespeedItisimportanttonotethattheillustratedgeneratingmodetrajectoryinFigforspeedsabovethecornerpointactuallyrepresentsanoptimisticouterlimitforthecurrentvectorlocusthatcanonlybeapproachedbutneverquitereachedforanactualcurrentregulateddriveThisistruebecausetheouterboundaryofthevoltageellipseatanyspeedcorrespondstosixstepvoltageoperation,representingaconditioninwhichthecurrentregulatorloopsarecompletelysaturatedSincethecurrentregulatorlosescontroloftheinstantaneousmachinephasecurrentsundersuchconditions,thecurrentvectorcommandmustbecontinuallyadjustedsothatitalwaysresidessafelyinsidethevoltageellipseHowever,itisdesirabletoapproachtheellipseascloselyaspossibleunderheavyloadconditionsinordertodelivermaximumpowerfromtheIPMmachine,takingfulladvantageoftheavailableinverterdcbusvoltageWiththisobservationinmind,itisclearthatanglebetweenthecommandedcurrentvectorandthenegativedaxisinFigmustbereducedastheshrinkingvoltageellipseprogressivelyintrudesonthecurrentlimitcircleforspeedsabovethecornerpointThiscontrolaction,illustratedinFig,providesthebasisforthenewgeneratingmodecontrolalgorithmdescribedinthenextsectionISISqqIqIdFluxWeakeningActionFigPlotofcurrentvectorsillustratingfluxweakeningactionduringgeneratingmodeoperationStarterAlternatorMachineShaftAngleTransducerTe*iqVDCLinkCapacitorVectorRotatorVdcVdcVdcTStart(ForStarting)Vdc*(ForGenerating)PISAControlModuleidVqe*Vde*Vqs*Vds*qqrVdcGateSignalsSpaceVectorModulatorVectorRotatorddtwwrqqrqqrFigBlockdiagramofISAcontrollerconfigurationBControllerConfigurationAtoplevelblockdiagramoftheISAcontrollerisprovidedinFigThisfigureincludesmanyofthefeaturesthattypicallyappearinhighperformancevectorcontrolconfigurationsutilizingsynchronousframecurrentregulationThatis,phasecurrentinformationiscombinedwithrotorpositionfeedbacktodevelopmeasurementsoftheinstantaneousidandiqthatarefedtothecurrentregulatorimbeddedintheblocklabeledSAControlModuleAnotherinputtothismoduleisthetorquecommandTe*thatisderivedfromeitherthestartingtorquecommandorthebusvoltageregulator,dependingonthesystem'soperatingmodeTheoutputsofthismodulearethevoltagecommandsvde*andvqe*inthesynchronousreferenceframeThesevoltagecommandsarethenconvertedbacktothestationaryreferenceframeusingasecondvectorrotatorbeforebeingappliedtoaspacevectormodulatorThismodulatordevelopstheinverterswitchingcommands,makinguseofthemeasuredbusvoltagevdctoinsureasmoothtransitionfromPWMoperationintosaturatedsixstepvoltageoperationunderallbusvoltageconditionsFigureshowsthedetailedstructureoftheSAControlModulethatappearsasablockinFigThecontrolcomponentsenclosedbytheinnerdashedlineboxinthelowerhalfofFigareresponsibleforfluxweakeningoperationandareonlyareactivatedatelevatedspeedswhenthecurrentvectorapproachestheprevailingvoltagelimitellipseatanygivenspeedUnderallotherconditions,suchaslowspeedstartingoperation,thefluxweakeningcontrollerisessentiallydormant,havingnoeffectonthecontrolactionoftheFigSAControlModuleThecontrolelementslyingacrossthetophalfofFigdominateitsresponseundersuchconditions,asdescribedbelowStartingOperationThevectorcontrolprinciplesforcontrollingtheISAmachinetodeliverhighstartingtorque(uptoNm)asamotorarewellestablishedintheliteratureandwillbesummarizedonlybrieflyhereSincestartingmodeoperationoccursonlyatlowspeedswherethevoltagelimitellipseisnotafactor,themaximumtorqueperAmptrajectoryinthesecondquadrantprovidesthepreferredoperatingpointsformotoringtorqueproductionThemaximumavailablestartingtorquefromtheISAmachineoccursatthepointinthesecondquadrantwherethemaximumtorqueperAmptrajectoryintersectsthecurrentlimitcircleTheSAControlModuleinFigexecutesthisstartingmodecontrolbyconvertingastartingtorquecommandTe*intothecorrespondingvaluesofdandqaxiscurrentcommands,idmandiqm,usingthefunctionblocksfandfandthepolartorectangularconversionblockTheseffunctionsarepreprogrammedwiththemaximumtorqueperAmptrajectorythatmatchestheIPMmachine'scharacteristicsThetwoffunctionsdevelopthedesiredcurrentvectortrajectoryinpolarcoordinatesascurrentamplitude|I|*andangleq*commands(seeFig)forconvenientcompatibilitywiththefluxweakeningcontrolalgorithmthatwillbedescribedinthenextsectionTheq*anglecommandpassesthroughtothepolartorectangularconverterunaffectedbythefluxweakeningcontrolalgorithmatlowspeedsduringstartingTheupperrightsideofFigrepresentsthestatorcurrentregulatorinthesynchronousreferenceframeTherearemanydifferentwaysinwhichsucharegulatorcanbeimplementedTheparticularimplementationshowninFigappliesfeedforwarddecouplingcompensationtotheoutputvoltagecommandsusingthemachine'ssteadystatevoltagerelations,sothat:vqss=rsiqmwr(LdsidmfPM)()vdss=rsidmwr(Lqsiqm)()PolarToRectVoltageCompensationBlockiqmidvdssvqe*qq*'|I|*Te*ModulationIndexCalculatorMthbb**FluxWeakeningControlModuleSAControlModluleASvdcGGIntegratorMaximumTorqueAmpFunctions<<bb**<<idmiqDDiqDDidvqssvde*vqe'vde'f(T)f(T)vqe*vde*qq**wwrMFigBlockdiagramofSAControlModuleGeneratingOperationDevelopmentofaneffectivefluxweakeningcontrolalgorithmprovidesthekeytoachievingextendedconstantpoweroperationtomeetthedemandinggeneratingmoderequirementsoftheautomotiveISAapplicationThenewalgorithmimplementedinthissystemworksbydirectlyreducingtheangleqofthecommandedcurrentvectorwithrespecttothenegativedaxisasillustratedearlierinFigThecontrolelementsthatimplementthisfluxweakeningactionareenclosedinthesubblocklabeledFluxWeakeningControlModuleinthelowerhalfofFigThismoduleexecutesthecurrentvectoranglereductionbymultiplyingtheanglecommandq*frommaximumtorqueperAmpfunctionfbyascalingfactorb*thatvariesbetweenandAccordingtothisapproach,onlytheangleofthecurrentvector,andnotitsamplitude,isdirectlycontrolledbythefluxweakeningalgorithmAslongasthevalueofb*is,theFluxWeakeningControlModuleexertsnoinfluenceonthecurrentvectortrajectorydefinedbythemaximumtorqueperAmptrajectoryThevalueofb*isdeterminedbyhowcloselytherequiredstatorvoltageapproachesthesaturatedsixstepvoltagevalueatanyinstantintimeSincetheISAdriveisdesignedforhighfrequencyPWMoperation,theinstantaneousPWMmodulationindex,M,canbeusedasaconvenientandsensitiveindicatorofthecurrentregulator’sproximitytototalsaturation(ie,M=)Themodulationindexvaluecanbeconvenientlycalculatedusingthesynchronousframedqvoltagecommands,vqse*andvdse*,asfollows:M=dc*eqs*edsV)v()v(p()whereVdcisthemeasuredvalueofthedclinkvoltageattheconverterinputterminalsAnyexcessvalueofMaboveapresetthresholdlevel,Mth(lessthanbutcloseto)isintegratedtoreducethevalueofb*(<b*<)thatscalesthecurrentvectorcommandangleaccordingtoq*’=b*q*ThisfeedbackloopachievesthedesiredfluxweakeningactioninFigbyswingingthecurrentvectorintowardsthenegativedaxisinordertoretainitwithintheprevailingvoltageellipseatthattimeinstantBythisaction,thevalueofthemodulationindexnaturallydecreasesasthecurrentvectoroperatingpointmovesawayfromthevoltageellipseboundary,establishingastableoperatingpointloopinthefluxweakeningregimeWhenthetorquecommandandorrotorspeeddropsufficientlysothatfluxweakeningisnolongerrequired,thefeedbackloopnaturallyrespondsaccordinglytoreduceitseffectonthecurrentvectorangleqThatis,thevalueofb*quicklyintegratesbacktowhenthemodulationindexdropsbelowitsthresholdvalueM*Thus,thefeedbackloopbecomespassivewithnoeffectonthevectorcontroloperationuntilfluxweakeningactionisrequiredagainUseofthemeasuredvalueofdclinkvoltageVdcinthemodulationindexcalculation()makesitpossibleforthecontrollertoadaptimmediatelytoanychangesinthebusvoltageThisfeatureisimportantinapplicationssuchasanautomotiveISAwherethedcbusvoltagecanbeexpectedtochangesignificantlydependingonthebusloadingandthevehiclebatterystateofchargeOntheotherhand,thisvoltagemeasurementcanbereplacedbyaconstantvalueinapplicationswherethedcbusvoltageisknownandwellregulatedwithinanarrowrange,eliminatingtheneedforthebusvoltagesensorThefluxweakeningalgorithmintroducedaboveisnaturallybipolar,workingaswellformotoringoperationasforgeneratingwhereitisprimarilyneededintheISAapplicationTheresultingmotoringtorqueenvelopealongthevoltageellipseboundaryfortheIPMmachineinthisISAapplicationisshowninFigThisfigureconfirmsthattherequiredNmforstartingwillbeavailableatlowspeedsduringoperationonthemaximumtorqueperAmptrajectoryIVCONTROLLERPERFORMANCEADriveSystemSimulationSteadystateanddynamicperformancecharacteristicsofthecompleteISAdrivesystemincludingthemachine,PWMinverterandthecontrollerhavebeeninvestigatedusingcomputersimulationMatlabSimulinkTMwaschosenasthepreferredsimulationsoftwaretoolforcarryingoutthisanalysisTheswitchingbehavioroftheinverterismodeledusingsixidealswitchesTheIPMmachineismodeledinthedqsynchronous

职业精品

用户评论

0/200
    暂无评论

精彩专题

上传我的资料

热门资料

资料评价:

/8
1下载券 下载 加入VIP, 送下载券

意见
反馈

返回
顶部

Q