综述2002 Sensorless control of induction motor drive

SensorlessControlofInductionMotorDrivesJOACHIMHOLTZ,FELLOW,IEEEInvitedPaperControlledinductionmotordriveswithoutmechanicalspeedsensorsatthemotorshafthavetheattractionsoflowcostandhighreliability.Toreplacethesensor,theinformationontherotorspeedisextractedfrommeasuredstatorvoltagesandcurrentsatthemotorterminals.Vector-controlleddrivesrequireestimatingthemagni-tudeandspatialorientationofthefundamentalmagneticfluxwavesinthestatororintherotor.Open-loopestimatorsorclosed-loopobserversareusedforthispurpose.Theydifferwithrespecttoac-curacy,robustness,andsensitivityagainstmodelparametervaria-tions.Dynamicperformanceandsteady-statespeedaccuracyinthelow-speedrangecanbeachievedbyexploitingparasiticeffectsofthemachine.Theoverviewinthispaperusessignalflowgraphsofcomplexspacevectorquantitiestoprovideaninsightfuldescriptionofthesystemsusedinsensorlesscontrolofinductionmotors.Keywords—Adaptivetuning,complexstatevariables,identifi-cation,inductionmotor,modeling,observers,sensorlesscontrol,vectorcontrol.NOMENCLATUREAllvariablesarenormalizedunlessstatedotherwise.Unityvectorrotators.Statorphaseaxes.Currentdensity,MMF.Denominator.Functionofcomplexspaceharmonics.Fieldpositionvector.Frequency.Observertensor.Directaxiscurrentsignal.Quadratureaxiscurrentsignal.Nonnormalizedrmsphasecurrent.Statorcurrentvector.Unbalancecurrentvector.Disturbancecurrentvector.Saturationcurrentvector.Couplingfactorofthestatorwinding.Couplingfactoroftherotorwinding.Mutualinductance.Mutualinductance.ManuscriptreceivedSeptember3,2001;revisedMarch11,2002.TheauthoriswiththeElectricalMachinesandDrivesGroup,WuppertalUniversity,42119Wuppertal,Germany([e-mail]).PublisherItemIdentifier10.1109/JPROC.2002.800726.Rotorinductance.Statorinductance.Numberofrotorbars.Numerator.Numberofpolepairs.Instantaneousreactivepower.Statorresistance.Rotorresistance.Effectivetransientresistance.Laplacevariable.Sectorindicatorvector.Electromagnetictorque.Loadtorque.DClinkvoltage.Rotor-inducedvoltage.Rotorslotharmonicsvoltage.Zerosequencevoltage.Leakage-dependentzerosequencevoltage.Nonnormalizedrmsphasevoltage.Vectoroftherotorinducedvoltage.Statorvoltagevector.Zerosequencevoltage.Disturbancevoltagevector.Switchingstatevectors.High-frequencyimpedance.1,2Sequenceinavectorproduct.GreekSymbolsCircumferentialpositionangle.Fieldangle.Errorangle.Statorcurrentangle.Fieldalignmenterror.Errorangleofcarriervoltage.Errorangleofcarriercurrent.Rotorpositionangle.Phasedisplacementangle.Totalleakagefactor.Totalleakageinductance.Normalizedtime.Mechanicaltimeconstant.Rotortimeconstant.0018-9219/02$17.00©2002IEEEPROCEEDINGSOFTHEIEEE,VOL.90,NO.8,AUGUST20021359Statortimeconstant.Rotorslipfrequency.Statorfundamentalexcitationfrequency.Frequencyof-coordinates.Angularmechanicalvelocityoftheequivalenttwo-polemachine.Rotorfluxlinkagevector.Statorfluxlinkagevector.Leakagefluxlinkagevector.SubscriptsComponentsinstatorcoordinates.Phases,windingaxes.Averagevalue.Carrier.Synchronouscoordinates.-coordinates.Maximumvalue.Minimumvalue.Negativesequence.Positivesequence.Perphasevalue.Rotor.Ratedvalue.Stator.satSaturation.slotSlottingeffect.componentofavectorproduct.-coordinates.Leakagefluxes.1Fundamentalquantity.SupersciptsInstatorcoordinates.Infieldcoordinates.Incurrentcoordinates.In-coordinates.Originatesfromstator(rotor)model.Referencevalue.Averagevalue.Estimatedvalue.Peakamplitude.Laplacetransform.Markstransienttimeconstants.Precedesanonnormalizedvariable.I.INTRODUCTIONACdrivesbasedonfulldigitalcontrolhavereachedthestatusofamaturetechnology.Theworldmarketvolumeisabout12000millionUS$withanannualgrowthrateof15%.Ongoingresearchhasconcentratedontheeliminationofthespeedsensoratthemachineshaftwithoutdeterioratingthedynamicperformanceofthedrivecontrolsystem[1].SpeedestimationisanissueofparticularinterestwithinductionmotordriveswherethemechanicalspeedoftherotorisgenerallydifferentfromthespeedoftherevolvingFig.1.Methodsofsensorlessspeedcontrol.magneticfield.Theadvantagesofspeed-sensorlessinduc-tionmotordrivesarereducedhardwarecomplexityandlowercost,reducedsizeofthedrivemachine,eliminationofthesensorcable,betternoiseimmunity,increasedreliability,andlessmaintenancerequirements.Operationinhostileenvironmentsmostlyrequiresamotorwithoutspeedsensor.Avarietyofdifferentsolutionsforsensorlessacdriveshavebeenproposedinthepastfewyears.Theirmeritsandlimitsarereviewedbasedonasurveyoftheavailablelitera-ture.Fig.1givesaschematicoverviewofthemethodologiesap-pliedtospeed-sensorlesscontrol.Abasicapproachrequiresonlyaspeedestimationalgorithmtomakearotationalspeedsensorobsolete.Thecontrolprincipleadjustsacon-stantV/Hzratioofthestatorvoltagebyfeedforwardcon-trol.Itservestomaintainthemagneticfluxinthemachineatadesiredlevel.Itssimplicitysatisfiesonlymoderatedy-namicrequirements.Highdynamicperformanceisachievedbyfieldorientation,alsocalledvectorcontrol.Thestatorcur-rentsareinjectedatawell-definedphaseanglewithrespecttothespatialorientationoftherotatingmagneticfield,thusovercomingthecomplexdynamicpropertiesoftheinduc-tionmotor.Thespatiallocat