永磁直線同步電機低速負載性能(中英文對照)

一、外文資料譯文：正弦PWM電壓源逆變器供電的永磁直線同步電機低速負載性能司紀凱陳昊汪旭東袁世鷹上官璇鷹〔1.中國礦業(yè)大學信息與電氣工程學院徐州2210082.河南理工大學電氣工程與自動化學院焦作454000〕摘要對于開環(huán)低速區(qū)由正弦PWM電壓源逆變器供電的永磁直線同步電機〔PMLSM〕而言，與工作在高速情況的PMLSM負載性能不同，本文采用場路耦合時步有限元的方法研究PMLSM驅動水平運輸系統的兩種負載工況：輕載與重載。結果顯示，PMLSM工作在重載情況下的負載性能較輕載優(yōu)，且電機的工作電流隨著負載的增大而減小。仿真與實驗結果驗證了該方法的有效性及正確性。關鍵詞：永磁直線同步電機，負載性能，正弦PWM，電壓源逆變器，時步有限元法，場路耦合1引言永磁直線同步電機〔PMLSM〕已廣泛應用于多種領域，因為該電機具有高效性、高精度的控制性等特點,從自動化的運輸操作系統到復雜精細的軍事設備都會運用到它。然而，對于在較低速情況下的PMLSM的負載性能的研究是非常必要的，并且同步旋轉電機和PMLSM在高速情況下也有很多不同的特征。PMLSM在低速情況下因為有多而有效的氣壓和低頻率，電機具有抗電感能力強的根本特性。很多PMLSM具有這些特性，因為適用于PMLSM的轉速和頻率是有限的。通過文獻【5】可以得出，適用于PMLSM的規(guī)格是一樣的。電機的運轉頻率是6HZ，磁極距必須是30毫米。時步有限元分析法的研究為正弦PWM電壓源逆變器供電的電機驅動作了依據，并且由于PWM電壓源逆變器，人們對于時間步長的價值觀也改變了。在文獻【6】中，作者在邊緣效應的根底上描述了鼓勵永磁同步電機的局部動態(tài)性能。對于PMLSM驅動的啟動和控制的相關方面已經有所研究。電機規(guī)格也是一樣的。電阻是7.6Ω，電感是17.6mH，最大轉速是2m/s。根據文獻【7】顯示可知，模擬電壓是7V，頻率是3Hz，負載驅動力是20N。電壓源逆變器供電的PMLSM的動態(tài)特性的滯后性，是考慮了在合成鋁板和固體回收鐵中的渦電流，并通過分析時步有限元法和無線網絡技術得出的。在文獻【3】中，適于PMLSM的規(guī)格如下。電阻是5.2Ω，電感是2.8mH，電機驅動的轉速是0.9m/s。文獻【8】已經呈現出PMLSM基于正弦交流電流源，如大電感和電阻率，的穩(wěn)態(tài)性能。但是，對于在低頻率下的有大的電阻率和電感、半導體的SPWM逆變器操作，動態(tài)性能指標的研究在上述文獻中比擬缺乏。因此，研究電機在不同負載下的動態(tài)性能是極其重要的。最近，通過精確的磁場分析，已經研究提出了電機的動態(tài)性能。其中的一種數學方法是基于有限元法的方法，它被越來越多的應用于精確探討不對稱磁場的動態(tài)性能。至于PMLSM，它有三相不平衡繞組、開放磁路、電阻率、電感系數、相位、諧波和電機電流。采用解析法和傳統的有限元法客觀地研究一個或兩個極點的周期邊界條件，是很困難的，另外考慮到連接外部SPWM變頻器和磁場的問題，因此，本文就采用有限元分析法研究電機在不同負載的情況下，其暫態(tài)過程的性能，如：推力、移動速度和繞組電流。由于PMLSM靠SPWM電壓源逆變器供電，電機的電流是不知道的，并且電機的電壓還包括許多諧波分量，這就使有限元分析法不是很理想了。因此采用研究負荷性能時步有限元法和場耦合法就可以很好的研究該系統。這篇文章提出了使用時步有限元法和場耦合法研究電機在不同負荷情況下的性能。以下將會系統的講解，在第二局部中，將對永磁交流同步直線電機進行描述。有限元模型在第三節(jié)中講解。在論文第四局部將會研究PMLSM在不同負載下的性能并進行仿真和總結。在第五和第六局部，就總結實驗結果并總結結論。2物理分析模型這個模型主要是由三相繞組和核心擴展插槽組成，其次是由永久性磁鐵和在鐵軛外表上別離出來的磁性組成。PMLSM的規(guī)格如下表1所示。其中含永磁磁鐵磁化的漏磁量等。PMLSM的性能規(guī)格就在下面的表格中。PMLSM規(guī)格表型材工程材料和單位相位3匝數90主要電樞材料鐵磁極距39mm槽距13mm主存材料永久性磁鐵寬度27mm其次高度7mm長度120mm鑲嵌外表型空隙5mm圖1物理模型的方法建立的永磁直線型同步電機主要局部2—齒輪3—開槽4—絕緣磁鐵材料5—永磁鐵6—鐵軛3PMLSM勵磁電路的數學模型把SPWM電壓源逆變器，電機邊緣效應影響因素考慮進去，采用勵磁電路方法計算電磁的暫態(tài)方程，解決向量電磁場的變化過程及電機的穩(wěn)態(tài)方程，由勵磁電路相結合的電磁場時步有限元方程，并說明在電樞繞組中的繞組電路電動勢方程。瞬變場的控制方程，電磁場是可變的，其依據是麥克斯韋方程式。如方程式〔1〕可示：其中Az——向量電磁場中z軸方向的分量Js——電流密度Jm——磁化密度μ——磁導率在摘要中，2-d模型可以被分為三角元素構成網孔。在運用伽遼金法后，運動方程的分析模型為：其中A——未知的潛在向量電磁場I——繞組電流S,C,T——系數G——等效的矩陣磁化電流密度在外磁場作用下，磁介質磁化后出現的磁化電流要產生附加磁場。等效磁化法被用來處理永磁型場。磁化強度的符號是M0.由于電機較大的空隙特點，PMLSM的電阻和漏磁電抗沒有被無視。根據歐姆定律和法拉第電磁感應定律，關于電動勢和電壓的產生的三相繞組式如方程【4】：其中ψ——感應電動勢Ll——自感系數R——線圈電阻U——線圈電壓其中N——有效的線圈匝數B——磁通密度S1——有效面積S2——有效面積適用于PMLSM的磁路和電路是不平衡的，從而固定連接器的電勢不等于零域上的電勢。因此電機的相位方程修改如下：其中U0——逆變器的輸出電壓g0——逆變器開關功能Ud——直流電壓采用麥克斯韋法計算PMLSM的電磁力，其中包含了所有種類的諧波成分。電機電磁力的正弦分量計算載于公式〔9〕。電機電磁力的垂直分量計算載于公式〔10〕。其中L1——繞組的有效長度L2——積分長度Bx——x軸方向的磁通密度By——y軸方向的磁通密度FT——正弦方向上的電磁力FN——垂直方向上的電磁力PMLSM的運動方程如下：其中m——質量v——速度FL——負荷重力仿真結果仿真結果圖形如下。恒定電壓是30V，模塊頻率是2Hz，輕負載是50N，重負載是130N，電機額定同步速度是0.156m/s，這與PMLSM實驗模型的參數是保持一致的。從仿真結果我們可以得到，空間磁場的功能元素及外部電路的狀態(tài)作用。由于靠電壓逆變器提供電壓，外部條件可以忽略不計。圖2是在50N負載下的三相電流的仿真圖形。圖3是驅動力。圖4是在50N負載下的速度。圖5—圖7是在130N負載下的仿真圖形。從圖2和圖5，我們可以看出在50N負載下的三相電流比在130N負載情況下的要大。因為PMLSM的磁路電樞繞組是開放的，不連續(xù)的。比擬圖3和圖7，我們可以看出PMLSM在130N負載下的驅動力更大。在圖4和圖7中可以看出，在130N負載的情況下，電機的性能更好，更穩(wěn)定。如果產生的適用于PMLSM的磁阻力減少，移動速度根本上是接近同步速度的，因為有許多諧波，速度要完全相同是不可能的?！瞐階段，b階段，c階段〕圖2在50N負載下的三相電流圖3在50N負載下的驅動力圖4在50N負載下不減少磁阻力時的速度圖5在130N負載下的三相電流圖6在130N負載下的驅動力圖7在130N負載下的速度實驗結果電壓和電流是通過傳感器來檢測的。速度是通過E6B2型號的旋轉編碼器測得的，這個轉速可以轉化為電機的直線速度。數據采集系統可以通過TurboC來編輯。圖8和圖11分別是在50N和130N情況下的三相電流。圖9和圖12是分別在兩種負載下的驅動力。圖10和圖13是在這兩種負載下的速度。通過仿真和實驗結果，我們可以看出，這兩種情況都是可以的。圖8在50N負載下的三相電流圖9在50N負載下的驅動力圖10在50N負載下的速度圖11在130N負載下的三相電流圖12在130N負載下的驅動力圖13在130N負載下的速度總結在上述內容中，勵磁電路耦合法中的時步有限元法和外部電路被用來分析專門適用于永磁交流同步電機在大阻力、大電感、大氣隙和三相不平衡的低速度的情況下的負載性能。分析結果外表，PMLSM在重載情況下的負載性能比輕載時好，并且電機的工作電流隨著負載的增大而減小。由于止動裝置的存在，PMLSM產生磁阻力的波動，同步轉速范圍的移動速度。如果引起的適用于PMLSM的開環(huán)控制的磁阻力降低，轉動速度將相當接近于同步速度。參考文獻[1]WangXudong,YuanShiying,JiaoLiucheng,etal.3-Danalysisofelectromagneticfieldandperformanceinapermanentmagnetlinearsynchronousmotor[C].IEEEInternationalElectricMachinesandDrivesConference,Cambridge,MAUSA,2001:935-938.[2]BianchiN.AnalyticalcomputationofmagneticfieldsandthrustsinatubularPMlinearservomotor[C].ConferenceRecord-IASAnnualMeeting(IEEEIndustryApplicationsSociety),Rome,Italy,2000,1:21-28.[3]BonGwanGu,KwangheeNam.AvectorcontrolschemeforaPMlinearsynchronousmotorinextendedregion[J].IEEETransactionsonIndustryApplications,2003,39(5):1280-1286.[4]GoreVC,CruiseRJ,LandyCF.Considerationsforanintegratedtransportsystemusinglinearsynchronousmotorsforultra-deeplevelmining[C].IEMD99,Seattle,Washington,USA,1999:568-570.[5]JungInSoung,HyunDongSeok.DynamiccharacteristicsofPMlinearsynchronousmotordrivenbyPWMinverterbyfiniteelementanalysis[J].IEEETransactionsonMagnetics,1999,35(5):3697-3699.[6]SangYongJung,HyunKyoJung,JangSungChun,etal.Dynamiccharacteristicsofpartiallyexcitedpermanentmagnetlinearsynchronousmotorconsideringend-effect[C].IEEEInternationalElectricMachinesandDrivesConference,Boston,USA,2001:508-515.[7]KwonByungIl,WooKyungIl,KimDuckJin,etal.Finiteelementanalysisfordynamiccharacteristicsofaninverter-fedPMLSMbyanewmovingmeshtechnique[J].IEEETransactionsonMagnetics,2000,36(4):1574-1577.[8]ShangguanXuanfeng,LiQingfu,YuanShiying.Analysisoncharacteristicsofpermanentmagnetlinearsynchronousmachineswithlargearmatureresistanceandsmallreactance[C].TheEighthInternationalConferenceonElectricalMachinesandSystems,Nanjing,China,2005,1:434-438.[9]TounziA,HenneronT,LeMenachY,etal.3-Dapproachestodeterminetheendwindinginductancesofapermanent-magnetlinearsynchronousmotor[J].IEEETransactionsonMagnetics,2004,40(2):758-761.[10]YamaguchiT,KawaseY,YoshidaM,etal.3-Dfiniteelementanalysisofalinearinductionmotor[J].IEEETransactionsonMagnetics,2001,37(5):3668-3671.[11]InSoungJung,SangBaeckYoon,JangHoShim,etal.Analysisofforcesinashortprimarytypeandashortsecondarytypepermanentmagnetlinearsynchronousmotor[J].IEEETransactionsonEnergyConversion,1999,14(4):1265-1270.外文原文資料信息[1]外文原文SiJikaiChenHaoWangXudongYuanShiyingShangguanXuanfeng[2]外文原文所在書名或論文題目：LOADPERFORMANCEOFPMLSMINLOWERSPEEDREGIONFEDBYSINUOIDALPWMINWERTER[3]外文原文來源：TRANSACTIONSOFCHINAELECTROTECHNICALSOCIETY出版社或刊物名稱、出版時間或刊號、譯文局部所在頁碼：Vol.23No.9Sep.2008網頁地址：二、外文原文資料：LOADPERFORMANCEOFPMLSMINLOWERSPEEDREGIONFEDBYSINUOIDALPWMINVERTERSiJikai1,2ChenHao1WangXudong2YuanShiying2ShangguanXuanfeng2〔1.ChinaUniversityofMiningandTechnologyXuzhou221008China2.HenanPolytechnicUniversityJiaozuo454000China〕ABSTRACTForthepermanentmagnetlinearsynchronousmotor(PMLSM)fedbysinusoidalPWMvoltagesourceinverterinthelowerspeedconditionwithoutfeedbackcontrol,loadperformanceisdifferentfromthePMLSMworkinginhighspeedregion.Thepaperadoptstime-stepfiniteelementmethodandfieldcircuitcouplingmethodtoinvestigateloadperformanceofthePMLSMtodrivehorizontaltransportationsystemwithlightloadandheavyloadconditionrespectively.ItisshownthatloadperformanceofthePMLSMintheheavyloadconditionishighlybetterthanthoseinlightloadoperationconditions,andoperationcurrentbecomeslowerwithloadincreasing.Thevalidityisverifiedbycomparisonsofsimulationandexperimentalresults.Keywords:Permanentmagnetlinearsynchronousmotor(PMLSM),loadperformances,sinusoidalPWM(SPWM)inverter,time-stepfiniteelementmethod,fieldcircuitcouplingmethod1IntroductionThepermanentmagnetlinearsynchronousmotor(PMLSM)hasbeenwidelyusedinmanyapplicationsfromtransportationsystemtoofficeautomationandmilitarydevicesbecausethemotorshavelotsofmeritsashighefficient,highaccuracypositioncontrol,etc[1-4].However,itisnecessarythatloadperformanceoflowerspeedofPMLSMisprofoundlyresearched,whichhaslotsofcharacteristicstodifferentfromrotatingsynchronousmachineandPMLSMinthehighspeedregion.PMLSMinlowerspeedregionhastheessentialcharacteristicsthattherearelargeratioofthemotorresistancetoinductanceandlargeleakageinductancebecauseoflargeandeffectiveairgapandloweroperationfrequency.LotsofPMLSMshavethecharacteristicsbecausethemovingtrackofPMLSMislimitedandthemoversteadystaterunningspeedofPMLSMisfinite.IntheRef.[5],specificationsofPMLSMwereasfollow.Themotoroperationfrequencywas6Hz,thepolepitchwas30mm.IntheliteratureFEAmethodforelectricmachinesdrivenbyPWMinverterwasproposedandthevalueoftime-stepwaschangedaccordingtotheswitchinglogicofPWMinverter.IntheRef.[6],theauthorspresentedthedynamiccharacteristicsofpartiallyexcitedpermanentmagnetlinearsynchronousmotorconsideringend-effect.ThestartingandcontrolcharacteristicsrelatedtothecapabilityinPMLSMdrivingwereinvestigated.Thespecificationsofthemotorwereasfollow.Theresistancewas7.6ΩofsampleA,theinductancewas17.6mH,themaximumspeedwas2m/s.AstheRef.[7]shown,thesimulationconditionwas7V,3Hzandloadthrustwas20N.Thedynamiccharacteristicsofthehysteresiscurrentcontrolledinverter-fedPMLSMwiththeconductivesheetsecondarywasanalyzedthroughthetime-stepfiniteelementmethodandmovingmeshtechnique,whichconsideringeddy-currentsinthesecondaryaluminumsheetandsolidbackiron.IntheRef.[3],thespecificationsofPMLSMwereasfollows.Theresistancewas5.2Ω,theinductancewas2.8mH,themotorwasrunningat0.9m/s.Ref.[8]hadpresentedthesteady-stateperformanceofPMLSMbasedonsinusoidalaccurrentsourcesuchaslargerratioofresistanceandinductance,andthemoverinandouttheprimary.Unfortunately,asforthePMLSMfedbySPWMinverteroperatedinloweroperationfrequencyregionwithlargerratioofresistanceandinductanceandlargerleakageinductance,thestudyofdynamicperformanceispoorinabove-mentionedliteraturesanditisimportanttoinvestigatethemotordynamicperformanceindifferenceloadsconditions.Recently,manynumericalmethodshavebeenproposedtoinvestigatemotor’sdynamicperformancethroughaccuratemagneticfieldanalysis.Oneofthenumericalmethodsbasedonthefiniteelementmethod,whichismoreandmoreusedtoaccuratelyinvestigatedynamiccharacteristicsofspecifyandnewmachinesstructuresorasymmetrymagneticfield,canconsidergeometricdetailsandthenonlinearofmagneticcircuit[9-11].AsforPMLSM,ithasthreephasewindingsunbalance,magneticcircuitopening,biggerratioofresistanceandinductanceofthephasewindings,andtimeharmonicforthemotorcurrentexistence.ItisdifficulttostudythemotorperformancesadoptingtheanalyticalmethodandtheconventionalFEMwithobjectiveofoneortwopolesconsideringperiodboundaryconditions,additionallyconsideringthelinkagequestionsofouterSPWMinverterandmagneticfield,thus,thepaperusestotalmodelofthemotorFEAtoattaintransientprocessperformancessuchasthrust,themoverspeedandwindingscurrentindifferentloadconditions.DuetothePMLSMfedbySPWMvoltagesourceinverter,thecurrentsofthemotorareunknownandvoltageincludeslotsofharmoniccomponents,theeffectofusingonetooloffiniteelementmethodisnotideal.Thustime-stepfiniteelementmethodandcouplingfieldcircuitmethodisadoptedtoinvestigateloadperformancesofthemotordrivinghorizontaltransportationsystem.Thepaperpresentssimulationtools,whichusingtime-stepfiniteelementmethodandfieldcircuitcouplingmethodandexperimenttoinvestigatethemotorperformancesintwoloadsconditions,lightloadandheavyload.Thepaperisorganizedasfollows.InsectionⅡ,theprototypePMLSMisdescribed.FEMmodelisestablishedinsectionⅢ.InsectionⅣsimulationresultsofPMLSMloadperformancesareattainedanddiscussed.InsectionⅤexperimentalresultsarepresented.Lastly,insectionⅥsomeconclusionsaredrawn.2AnalysismodelTheprimaryiscomposedofthree-phasewindingsandcoreopenedslot,andthesecondaryconsistsinpermanentmagnetsandtheseparatedmagnetismpiecewhichplacedonthesurfaceoftheironyoke.SinglesidetypeshortprimaryandsurfacemountedPMLSMareshowninFig.1,inwhichpermanentmagnetmagnetizationisunanimoustoairgapfluxaxis,leakagefluxinpolesintervallowerandcraftworksimple.ThespecificationsofPMLSMareshowninTable.TablePMLSMspecificationsFig.1PhysicalmodelofsurfacepermanentmagnetlinearsynchronousmotorTheprimary2—Tooth3—Slot4—Materialofinsulatingmagnet5—Permanentmagnet6—Thesecondaryyoke3Field-circuitcouplingmathematicmodelofPMLSMTotakecircuitfedbySPWMvoltagesourceinverterandthemotorendeffectsintoaccount,thepaperadoptsfield-circuitcouplingmethodtocalculateelectromagnetictransientprocess,solveequationvariablesofmagneticvectorpotentialandthemotorphasecurrent,whicharecombinationofelectromagneticfieldtime-stepfiniteelementEqu.andthreephasewindingscircuitequations.byelectromotiveforceinthearmaturewindings.Transientfieldgoverningequations.inwhichAzdenotesmagneticvectorpotentialisvariableareshowninEq.(1)accordingtoMaxwellequations.whereAz——z-axiscomponentofmagneticvectorpotentialJs——CurrentdensityoftheprimarywindingsJm——Equivalentmagnetizingsurfacecurrentdensityofpermanentmagnetμ——ThepermeabilityInthepaper,the2-Dmodelissubdividedintosmalltriangleelementstoformameshthatcoverstheentireregionadoptingn-orderunitbasicfunctionandlinearinterpolation.AfterapplyingtheGalerkinmethod,thegoverningequations.fortheanalysismodelisexpressedaswhereA——Unknownmagneticvectorpotential(AisusedinEq.(1)withdifferentmeaning)I——CurrentinthewindingsS,C,T——CoefficientrespectivelyG——CorrespondingmatrixofequivalentmagnetizationcurrentdensityEquivalentmagnetizingsurfacecurrentmethodisadoptedtodealwithNdFeBtypepermanentmagnet,whichisuniformitymagnetization,regulationshape,andlineardemagnetization.IntensityofmagnetizationsignisM0.PMLSMresistanceandleakagereactanceisnotneglectedduetothemotorwithlargeairgapcharacteristic.AccordingtoOhmlawandFaradayelectromagneticinductionlaw,relationofelectromotiveforceandvoltageproducedtheprimarythree-phasewindingsisshowninEq.(4).whereψ——ThewindingsfluxlinkageLl——ThemotorleakageinductanceR——WindingsresistanceU——WindingsphasevoltagewhereN——WindingeffectiveturnsB——FluxdensityS1——WindingeffectiveareaintheslotS2——CoupledeffectiveareaoftheprimaryandthesecondaryToPMLSMmagneticcircuitandelectriccircuitareunbalance,thuselectricpotentialoftheconnectorofstarpointisnotequaltozeroandthemotorphaseequations.shouldbechangedasfollows.WhereU0——Outputvoltageoftheinverterg0——Theinverterswitchon-offfunctionUd——DirectvoltageofbuslinkMaxwell’sstresstensorisadoptedtocalculatePMLSMelectromagneticforce,whichincludesallkindsofharmonicscomponentelectromagneticforce.ThemotorelectromagneticforcetangentialcomponentisshowninEq.(9).ThemotorelectromagneticforcenormalcomponentisshowninEq.(10).whereL1——WindingeffectivelengthL2——IntegralspaceBx——x-axisfluxdensitycomponentintheairgapfieldBy——y-axisfluxdensitycomponentintheairgapfieldFT——ElectromagneticthrustforceFN——NormalelectromagneticforceMovementequationofPMLSMisshowninEq.(11).wherem——Massv——ThemotormovervelocityFL——Loadforce4SimulationresultsThesimulationconditionsareasfollows.Linevoltageis30V,modulefrequencyis2Hz,lightloadis50Nandhighloadis130N,themotorratedsynchronousspeedis0.156m/s,whichareidenticaltoexperimentalPMLSMparameters.Thesimulationresultsareattainedfromcosimulationoffiniteelementfunctionofmagneticfieldandspacestatefunctionofoutercircuit.Themotorvoltageresultsareneglectedbecausethevoltageinverterisnotalmostaffectedbytheouterconditions.Fig.2showssimulationresultsofthreephasecurrentinload50Ncondition.Fig.3displayssimulationresultofthrustforce.InFig.4,themoverspeedsinload50Nconditionareshown.Shortdashlinedenotesthemoverspeedinload50NconditionundereliminationofPMLSMdetentforcebychangingendshape.Fig.5～Fig.7showrespectivelysimulationresultsofthree-phasecurrent,thrustforce,speedofthePMLSMinload130Ncondition.FromFig.2andFig.5,itisshownthatthethree-phasecurrentsofthePMLSMinload50Nconditionarelargerthanthoseofinload130Ncondition,accordingtoeveryloadconditionthemotorphasecurrentisunbalancethataphasecurrentvalueisalmostclosetobphasecurrent,butbothislargerthancphasecurrentvaluebecausethePMLSMmagneticcircuitisopenandarmaturewindingsarediscontinuous.IntermsofcomparisonwithFig.3andFig.6,wecanknowthatthetendencyofthethrustforceofthePMLSMinload130Nconditionisfavorable.AsshowninFig.4andFig.7,inload130Ncondition,thestaringperformanceofthemotoriswellandthereislittleundulation.IfthedetentforceproducedarmaturecorelengthofPMLSMisreduced,themoverspeedisbasicallyclosetothesynchronousspeed,butitisimpossiblethatitisabsolutelysameassynchronousspeedbecausetherearelotsofharmoniccomponentsincurrentfedfromSPWMvoltageFig.2Three-phasecurrentinload50NconditionFig.3Thrustforceinload50NconditionFig.4Speedwithandwithoutreducingdetentforceinload50Nconditioninverterandairgapfieldisunsinuso-idalevenifdrivensystemiswithfeedbackcontrol.Fig.5Three-phasecurrentinload130NconditionFig.6Thrustforceinload130NconditionFig.7Speedinload130Ncondition5ExperimentalresultsExperimentalinvertertypeisFR-A241E-55KinverterofMitsubishicorp.Voltageandcurrenthallsensorsareusedtodetectsigns.ThemoverspeedisattainedbytherotatingencoderforE6B2type,whoserotatingspeedcanbeconvertedintothemotorlinespeed.SoftwareofthedatacollectionsystemiseditedthroughTurboClanguage.Fig.8andFig.11showthree-phasecurrentinload50Nand130Ncondition,respectively.ThrustforceofthemotorintwoloadsconditionisshowninFig.9andFig.12.FromFig.10andFig.13,itisshownthattherearetwospeedcurvesinload50Nand130Ncondition.Bycomparisonsofsimulationandexperimentresults,wecanseethatbotharehighlycompatible.Fig.8Three-phasecurrentinload50NconditionFig.9Thrustforceinload50NconditionFig.10Speedinload50NconditionFig.11Three-phasecurrentinload130NconditionFig.12Thrustforceinload130NconditionFig.13Speedinload130Ncondition6ConclusionsInthepaper,field-circuitcouplingmethodofthetime-stepfiniteelementmethodandouterelectricpowercircuitisutilizedtoanalyzespecialloadperformancesoflowerspeedofPMLSMwithlargeratiooftheresistancetotheinductance,largeairgapandthree-phaseunbalance.AnalysisresultsshowthatloadperformancesofthePMLSMintheheavyloadconditionarehighlybetterthanlightloadoperationconditions,andoperationcurrentbecomeslowerwithloadincreasingbecauseofthelargeratiooftheresistancetotheinductanceandlargeairgap.Duetoexistenceofdetentforce,thePMLSMmoverspeedfluctuatesintherangeofthesynchronousspeed.IfthedetentforceofPMLSMwithopenloopcontrolisreduced,themoverspeedisquiteclosetosynchronousspeed.Refrerence[1]WangXudong,YuanShiying,JiaoLiucheng,etal.3-Danalysisofelectromagneticfieldandperformanceinapermanentmagnetlinears