外文翻译-永磁同步电机的直接转矩控制

英文原文ADirectTorqueControlforaPMSMG.Mino-Aguilar,A.MichelleDomnguez,R.Maya,R.Alvarez,L.Cortez,G.Muoz,F.Guerrero,S.Maya,A.M.Rodriguez,F.Portillo,H.Azucena.BenemritaUniversidadAutnomadePuebla,Mexico.AbstractForalongtime,permanentmagnetsynchronousmotors(PMSM)wereonlyappliedinsomeparticularfields,e.g.forservodrives.However,inrecentyearsPMSMgainedincreasingimportanceinnoveldomainslikeautomotivehybriddrivetrains.ForMexico,thisboomrepresentsavaluableopportunityforuniversitiesandresearchinstitutions,sothattogetherwithMexicanindustryoftheElectricVehicle(EV)formingpartnershipsthatresultinaninfrastructurethatwillenablethecountrytodevelopitsowntechnologyintermsofEV.Thispaperpresentsacompetentandnotcomplexdirecttorquecontroller(DTC)forPMSMdrives.1.Introduction.Thestudyoftheelectricmachineandcontrolhasbeentoughenedbytwomajoruniversalproblems:pollution(water,ground,andtheatmosphere)andoverpopulation.Thislastonehascreatedinpartextremelyhighdemandsofpowerandpersonalmeansoftravel,andthishasinevitablyresultedinthefirst.Anincreaseofelectricmotorsefficiency,whichconsumesmorethanhalftheelectricitygenerated,canresultinanimportantelectricalenergysavings.Inrecentyearsthetrendhaschangedfromnotonlyimprovingthedesigncharacteristicsoftheelectricmachinebydevelopingbetterwaystocontrolthem,butalsousingdigitalsystems,powerelectronicsandadvancedtechniquesofcontrol.Inparticular,thethree-phaseinductionmotors(IM)arecommonlyusedinindustry,becausenotonlydotheyhaveasimpledesign,butalsotheyarereliableandinexpensive.Thepermanentmagnetsynchronousmotors(PMSM)areincreasinginpopularityduetotheirhighefficiencyandpowerdensity.Manymotorapplicationsrequireaprecisecontrolofbothspeedandtorque,whichispossiblebyusingfrequencyconvertersbetweenthepowerlinesandthemotor.Anotherwaytosaveelectricityisbyadjustingthemotorspeed.Nowadaysitcanbesaidthatthetrendofusevariablespeeddriveshasincreasedsignificantly,especiallywherethetorqueandspeedaretobevariedtocontrolthespeed,position,flowandtorque.Amongthevariousmethodsusedtocontrolmotors,thedirecttorquecontrol(DTC)techniquehasanimportantplace.Thistechniqueinvolvestherespectivecontrolofthetorqueandfluxlinkagebyselectingapropervoltagevector.TheessentialideaofDTCistopickanappropriatevoltagevectorusingapredefinedswitchingtable.Thisisachievedbycalculatingtheinstantaneoustorqueandfluxfromthestatormachinevariables.Thetorqueandfluxarecontrolleddirectlyandindependentlythroughtheselectionofoptimuminverterswitchingstatesandlimitingtheerrorsofthefluxandtorquebyhysteresiscontrollers.DTCsoperationisillustratedinFig.1.TheDTChasadvantagesforimplementingadriveroflow-costandhighperformance,becausetheonlyparameteroftheengineinvolvedisthestatorresistance.Thewell-knownDTCisimplementedinMatlab/SimulinktoobservetheperformanceofthePMSMatdifferentspeedsandloadingconditions.BlockswereimplementedforthemodelssuchastheMSIP,theDTC,theparktransformationandtheinverter.2.DirectTorqueControl(DTC).Directtorquecontrol,isavectorcontrolmethod,Figure1.DiagramofatypicalDTCPMSMdrive.whichincorporatesthecontrolvoltageconverterinsidethespeedcontrolalgorithm.Theoptimalswitchingsequenceoftheinvertertransistors(VSI)isdirectlybasedonthestateoffluxandelectromagnetictorqueofthePMSM.ThenecessarycalculationsareperformedusingtheequationsfromthemodelofthePMSMaswellascurrentsandvoltagesinthestatorterminals.ThegeneralDTCpremisesare-Theestimatedinstantaneousfluxvectorshouldremainclosetoitsreference.-Theestimatedtorqueshouldremainclosetoitsreference.-Thedynamicenginebehaviorcanbestudiedfromsuddenchangesthatmayoccurbothinthereferencespeedoftherotororfromthetorquereferencevalue.Theseassumptionsinvolvefourmajortasksa)Determinetheappropriatevaluesofthereferences.b)Calculatetheactualvaluesofthefluxvectorandelectromagnetictorque.c)Makeanappropriateinterpretationoftheerrorsbetweenestimatedvaluesandtheirreferences.d)Manipulatethestateoftheinvertertoreducethespeederror.Fig.1showstheDTCforaPMSMblockdiagram.Onecansee,thatonceonehastheestimatedandreferenceinstantaneousvaluesofelectromagnetictorqueandstatorflux,weproceedtocalculatetheerrorbetweenthem;theseerrorareusedasinputforthehysteresiscontrollers.Theoutputlevelsachievedinthisstageofthecontrolareinputsignalstotheblockthatisresponsibleforfindingtherightvectortogetridoftheerrorrate.ThisprocedureismadeforeachsamplinginstantfordrivingthePMSMtothedesiredspeedvalue3.Fluxandtorquereference.Thehysteresiscontrolleroutputisgeneratedaftertheestimatedfluxiscomparedwithitsreference.However,thisreferencevalueisobtainedbasedontheelectromagnetictorquereference7.Thestatorfluxmodulecanbeexpressedas(1)1/22ssDsQwheresisthestatorfluxvector,sDandsQarethesDandsQaxesstatorfluxesgivenby(2)sDdsmLi(3)sQqsQiLdandLqarethedirectandquadratureinductances,isDandisQarethesDandsQstatorcurrentsandmisthefluxfromthepermanentmagnets.Using(1)-(3)themagnitudeofstatorfluxcanbeexpressedas(4)1/22sdsDmsQLiLiandconsideringthattheelectromagnetictorqueisgivenby(5)wherePisthenumberofpolepairs(5)3/2emsQdqsDQtPiLiinwhich,themaximumtorqueperunitofcurrentisobtainedbyconsideringisD=0,then(5)isas(6)3/2emsQtiThusthecurrentproducedbythetorqueis(7)/3semitPSubstituting(7)in(4)thefunctionrequiredtoobtainthereferencefluxis(8)1/22/srefdsDmqerfmLiLtpThereferencetorqueisgeneratedthroughthePIcontrollerforspeed.4.Estimatedflux.Usingthepositionoftherotorandthestatorcurrents,thestatorfluxestimationisgivenbythefollowingequationwhereristherotorangle,Lsandisareinductancematrixandcurrentvectorofthestator(9)jrjrsssDsDsmejLie5.Estimatedtorque.Usingtheestimatedfluxesandthemeasuredstatorcurrentstransformedintothestationaryreferenceframetheelectromagnetictorquecanbecalculatedusing(13)3/2esDsQtPii6.Estimatedangle.Itispossibletoestimatethestatorfluxanglesthroughitsstationaryreferenceframecomponentssotheangleiscalculatedusing(14)1tan/ssQsD7.Hysteresiscontrollers.Whentheestimatedvalueofthevariableisfarfromitsreference,itwillbenecessarytouseasuitablevoltagevectortomodifyitsoitstayswithincertainlimitsaroundthereference.Hysteresiscontrollersaimtomaintainthetorqueandfluxerrorswithinupperandlowerlimitsallowed,sothatwhenevaluatingwithintheselimitsanoutputlevelisobtainedtoknowthestatusofthevariable.8.Switchingtable.Themainobjectiveoftheswitchingtableisthegetthefastesttorqueresponse.TheswitchingtablepresentedbyTakahashiandNoguchi(Table3)takesintoaccountthesector(1),(2),(6)inwhichthestatorfluxvectorislocatedinstationaryreferenceframe(sD,sQ)andthedigitaloutputlevelsofthefluxandtorquehysteresiscontrollers(ds,dTe).Fig.2showsthateachsectorcovering60electricaldegreesbytheregions(1),(2),(6),wherethesector1coversfrom30upto30,sector2from30to90andsoonuntil330isreached.TheplaneisdefinedbytheaxessDandsQwheresDisatzerodegrees.AsshowninFig.3,thedeterminationofthesectorismadewithrespecttotheanglesatwhichthefluxvectorsislocated.Oncelocatedthesectorandhavingthestateofthesignalsds,dTewhichindicatewhetherthevariableshouldbeincreasedordecreased,thevoltagevectorappliedateachinstantistobedeterminate.Fig.3showsasituationinwhichthefluxvectorsisinthesector(2)atthelowerlimitofhysteresisband.Ifafluxincrementisrequired,itisnecessarytoapplyavoltagevectortoincreasetheradiusofthiscircle,thevectorsthatachievethisgoalare1,2and3.sdsss*+s0Table1.FluxhysteresisControllersoutputTedTeTeTe*+Te-1Table2.TorquehysteresiscontrolleroutputdsdTe(1)(2)(3)(4)(5)(6)11234561-161234513456120-1561234Table3.CommutationtablebyTakahashiandNoguchiFigure2.Sectorsdistributiontolocatefluxposition.Figure3.Exampleofpositioningthefluxvectorinsector2.TovarythetorqueTeanactionisrequiredontheloadangle(),thatis,avectorwhichcausesadisplacementonsmustbechosen.InthecaseofFig.3,vectors3and4willincreasethetorque,5and6willdecreaseit.Accordingly,theapplicationofdifferentvectorswillchangethesbehaviorindifferentways(sizeandposition).9.Simulation.ThedynamicmodelequationsofthePMSMandallproceduresinvolvedintheDTCcanbeimplementedthrusimulation.ThePMSMisdescribedusingSIMULINKblocks.Theinitialpositionandtheloadareconsideredasinputstosystemandtheenginesmathematicalrelationshipsaredefinedthroughsubsystems.ChangesbetweenreferenceframesareperformedthroughParktransformations.TocontrolthePMSM,ismadethrutheimplementationoftheDTC.Someoftheblocksincludetheestimatorsofflux,torqueandposition,theselectionofthesectorinwhichthestatorfluxvectorispositioned,hysteresiscontrollers,thePIcontrollerforthespeed,aswellasothers.Fig.4showstheDTCimplementation.Firstcurrentandrotoranglearesampled.Oncesampledanaxistransformationofthecurrentstakesplace,thosecurrentsareusedtocalculatethestatorfluxcomponentswhichtogetherwiththecurrentsareusedtoobtaintheestimatedflux,torqueandangle.TheseestimationsoffluxandtorqueareenteredalongwiththeircorrespondingreferencesasinputsignalstotheblockscalledSubsystemandSubsystem1,whicharethehysteresiscontrollersoftheDTC.Theoutputsignalsofthesecontrollerstogetherwiththesectorselectionblockoutputgothroughtheswitchingtablewheretheoptimalvectorshallbeobtained,therebyachievingnecessarychangesinthemotorfluxandtorquetoreachthereferencespeed.Tofindthesectorinwhichthestatorfluxislocated,theblockcalled“Look-UpTable”isused,whichevaluatestheinputwithrespecttocertainkeypointspreviouslyestablished.The“Look-UpTable”simplydeliverstheoutputdatathatindicatesthematchingsector.10.Results.Fig.5showstheactualmotorspeedcomparedwithitsreferencepreviouslysettoaconstantvalueof1500rpm.Fig.6ashowsthefluxbehaviorandFig.6billustratesthetorquebehavior,itcanbeseenhowbothremainclosetotheirreferencevalues.Figure4.SIMULINKblockdiagramoftheDTC.Figure5.Constantreferencespeedat1500rpm.Figure6.Comparisonofestimatedvaluesagainsttheirreferences.Withconstantreferencespeedandchangesinload,inFig7canbeseenthatwhenloadchangesthereisaminorrepercussioninspeed.Atthemomentwhentheloadincreases,therotorspeedtendstodrop,thiscanclearlybeseenatthe1.5seconds,wheretheloadwasincreasedfrom1Nmto3Nm,thenthereisanoppositeeffectwhenloadgoesdown,thespeedincreasesforafewmomentstore-establishitsreference.Fig.8showstheestimatedtorqueasittriestofollowitsreferenceformedaroundtheload.InFig.9aavariablespeedisintroduced,themotorspeedfollowsitsreferenceandthereareonlyminorvariationswhenloadisincreasedordecreased.Fig9billustratestheloadappliedtothemotor.InFig.9ccanbeseenhowtheelectromagnetictorquehastocompensatebothspeedandloadincreases,sothatforafewsecondsthereferencetorquehasmorenoticeablevariation,thiscanbeseenat0.5,2and2.5secwhenchangesinspeedareintroduced.Figure7.(a)Constantreferencespeedat1000rpm,(b)loadvariations.Figure8.BehavioroftheelectromagnetictorqueFigure9.(a)Variablereferencespeed,(b)loadvariations,(c)electromagnetictorquebehavior.11.Conclusions.Althoughseveraltechniquesofcontrolexist,themainobjectiveofthispaperwastheimplementationofDTCforaPMSM,whichisbasedonthecontrolofthemotorstorqueandfluxseparately.Bothtorqueandfluxestimatorswerebeenimplemented,statorfluxanglewasalsocalculated.Fromdifferentreferencespeedshasbeenobtainednecessaryreferencevaluesforbothelectromagneticcomponents.Inadditiontothis,also,throughtheblocksLook-upTableandDirectLook-uptable,werederivedboththeareainwhichthefluxvectorislocatedandtheoptimalswitchingvectorappliedtotheengine.TheperformanceofthistechniquewastestedbysimulationsdriveninMatlab/Simulink.Thesimulationresultsshowdesirablebehavior.Itcanbeseenthatthecontrolmeetsthedemandsofthesystemquickly,whatcanbetranslatedasafriendlyspeedcontrol.Itwasillustratedhowthestatorfluxandthemotortorquecanbeheldundercontrolthroughvoltagespacevectors.Ithasbeendemonstratedthatbothinstantaneousstatorfluxvector,andelectromagnetictorqueproducedinaPMSM,canbeestimateddirectlyfromthecurrentsandvoltagessensedinterminalsofthemotor.12.References1CasadeiD，FilippettiF，RossiC，stefaniAMagnetsFaultsCharacterizationforPermanentMagnetSynchronousMotorsJIEEETransonMagnetics，2009，42(6)：1307-13142KangG，HurJ，NamH，etalAnalysisofIrreversibleMagnetDemagnetizationinLine-StartMotorsBasedontheFinite-ElementMethodJIEEETransonMagnetics，003，33(6):1488-1491.3ChenZhiqian，TomitaMutuwo，DokiShinji，etalAnextendedelectromotiveforcemodelforsensorlesscontrolofInteriorpermanent-magnetsynchronousmotorsJIEEETransonIE，2003，50(2)：288-295.4QFengchunMagneticstabilityofpermanentmagnetmaterialsJJournalofMagnMaterDevices，1999，29(5)：26-31(inChinese)中文译文永磁同步电机的直接转矩控制摘要在过去很长一段时间，永磁同步电机只应用在某些特殊领域，如：伺服驱动器。然而,近年来永磁同步电机在新的领域里显得越来越多的重要，如自动混合驱动机构。对于墨西哥，这种发展在大学和研究体系是个有价值的时机，使墨西哥的电动车产业有自己的先进技术，促使整个国家的工业发展。本文介绍了一种功能强大而且简单的直接转矩控制器。1.论文简介电动机的研究和控制主要有两个常见的问题：污染（水、土壤和空气）和人口过多。后者在某种程度上造成对能源的极大需求，不可避免地导致第一个问题的产生。电动机的使用消耗一半以上的电能，其效率的提高是节省电力能源的重要方面。近年来不仅是通过控制电机来提高特性，而且使用数字系统，电力电子和更高级的控制技术。尤其是三相感应电动机通常用于工业领域，因为它们不仅设计简单，而且成本低，性能可靠。永磁同步电机倍受欢迎的原因取决于他们的高效和功率密度。许多电动机转矩和转速的精确控制需要在输电线和电机之间安装变频器。另一种节省电力的方法是通过电动机调速。如今可以说使用变速传送装置更让人观注，尤其是通过改变转矩和转速来控制速度，转向，电流和扭矩。在所使用的各种控制电机的方式之中，直接转矩控制技术已经是重要的方法。这种技术包含通过选择适当电压矢量完成转矩和磁链各自的控制。直接转矩控制的基本思想是选择一个适当的电压矢量使用一个预定义的开关表。通过计算定子变量中瞬时的转矩和电流来完成。转换开关最佳状态的选择以及通过磁滞控制器对电流和转矩误差的限定直接控制了转矩和电流。直接转矩控制的方法如图1所示。直接转矩控制的优点可以执行低成本和高性能的驱动程序，因为发电机的参数仅包含定子的阻抗值。众所周知，直接转矩控制可以用MATLAB仿真永磁同步电动机在不同转速和负荷条件下执行。正如执行MSIP模型，直接控制转矩，磁头转换和逆变。2.直接转矩控制（DTC）图1.典型永磁同步电机直接转矩控制图直接转矩控制，是一种矢量控制方法，这种方法包含控制电压转化器内的速度控制算法。变速指示器的最佳转换顺序是基于永磁同步电动机的定子电流和电磁转矩。从永磁同步电动机的模型列出的方程式，并计算出定子两端的电流和电压.一般的直接转矩控制前提是-估计瞬时电流矢量应接近它的参数。-估计转矩应保持接近它的参数-动态引擎可以从同时出现转速参考值或转矩的参考值突变上研究。这些假设包含四项主要工作：a)确定适合的参考值。b)计算电流矢量和电磁转矩实际值。c)对估计值和参考值之间的误差给予适当的解释。d)操纵反相器的状态以减少速度误差。图1描述了永磁同步电动机直接转矩控制框图。一方面可以看出，定子电流和电磁转矩的瞬时值与估计值，我们进而可以计算出它们之间的误差。这些误差量被用来做磁滞控制器的输入。输出级在输入信号块这个控制阶段去掉误差率。这个过程有利于每一个驱动永磁同步电动机采样瞬间理想转速值。3.电流和转矩参数磁滞控制器输出产生在电流估计值与它的参考值相比之后。然而，这个参考值包含基于电磁转矩参考值7.定子磁通模块表达式为：(1)1/22ssDsQ其中s是定子磁通矢量，sD和sQaresD轴和sQ轴(2)sDdsDmLi(3)sQqsQLiLd和Lq是电感的正弦，isD和isQ是定子电流，m是永磁铁的磁通。用（1）-（3）定子磁通量可以表示为：(4)1/22sdsDmsQLiLi电磁转矩由（5）给出，其中P是极对数。(5)3/2emsQdqsDQtii加上条件isD=0，（5）可以写成:(6)/emsQtPi因此，转矩为：(7)2/3sQemit用式（4）代替式（7）得磁通参考值为：(8)1/22/3srefdsDmqerfmLiLtp参考转矩通过PI调节器产生。4.估算磁通利用转子位置和定子中的电流，定子电流近似值由方程式7给出，其中r是转角，Ls和is是感应系数矩阵和定子电流矢量。(9)jrjrsssDssmejLie5.近似转矩利用近似磁通和测量定子电流转变成静态参考系，电磁转矩可以用7式计算。(13)3/2esDsQtPii6.近似角度值通过定子磁通量的静态参数估计它的磁通角度s，所以这个角度可以用下式计算(14)1tan/ssQsD7、磁滞控制器当近似值与参考值差别很大时，将需要用一个适当的电压矢量去修改它，所以它要保持在参考值的某一范围内。磁滞控制器的目的就是使转矩和磁通的误差保持在上下允许误差的范围之内，因此评估输出级要先获取变量的状态。8、转换表转换表的主要目的是获得快速转矩响应。转换表最早是由Takahashi和Noguchi（表3）二人用于计算定子磁通矢量位于静态参数轴（sD,sQ）和转矩控制器(ds,dTe)的数字输出控制级扇区(1),(2),(6)。图2描述了(1),(2),(6)将每个扇区分为60个电角度，扇区1从30到30,扇区2从30到90，依次类推直到330。该平面按sD轴sQ轴定义，sD定为0度。剩余角度s磁通矢量s的位置如图3所示。一旦发生信号ds的状态，资料表明,变量应该增加或减少，电压向量在每一个瞬间被确定。磁通矢量s的情况为磁滞簇的最低限制中扇区(2)。如果需要增加磁通，必须运用电压矢量增加圆的半径，这些向量为1,2和3。表1.磁滞通量控制器输出表2.磁滞转矩控制器输出表3.由Takahashia