Permanent Magnet Synchronous Motor

DigitalSignalProcessingSolutionforPermanentMagnetSynchronousMotorApplicationNoteLiteratureNumber:BPRA0442IMPORTANTNOTICETexasInstruments(TI)reservestherighttomakechangestoitsproductsortodiscontinueanysemiconductorproductorservicewithoutnotice,andadvisesitscustomerstoobtainthelatestversionofrelevantinformationtoverify,beforeplacingorders,thattheinformationbeingreliedoniscurrent.TIwarrantsperformanceofitssemiconductorproductsandrelatedsoftwaretothespecificationsapplicableatthetimeofsaleinaccordancewithTI’sstandardwarranty.TestingandotherqualitycontroltechniquesareutilizedtotheextentTIdeemsnecessarytosupportthiswarranty.Specifictestingofallparametersofeachdeviceisnotnecessarilyperformed,exceptthosemandatedbygovernmentrequirements.Certainapplicationusingsemiconductorproductsmayinvolvepotentialrisksofdeath,personalinjury,orseverepropertyorenvironmentaldamage(“CriticalApplications”).TISEMICONDUCTORPRODUCTSARENOTDESIGNED,INTENDED,AUTHORIZED,ORWARRANTEDTOBESUITABLEFORUSEINLIFE-SUPPORTAPPLICATIONS,DEVICESORSYSTEMSOROTHERCRITICALAPPLICATIONS.InclusionofTIproductsinsuchapplicationsisunderstoodtobefullyattheriskofthecustomer.UseofTIproductsinsuchapplicationsrequiresthewrittenapprovalofanappropriateTIofficer.QuestionsconcerningpotentialriskapplicationsshouldbedirectedtoTIthroughalocalSCsalesoffice.Inordertominimizerisksassociatedwiththecustomer’sapplications,adequatedesignandoperatingsafeguardsshouldbeprovidedbythecustomertominimizeinherentorproceduralhazards.TIassumesnoliabilityforapplicationsassistance,customerproductdesign,softwareperformance,orinfringementofpatentsorservicesdescribedherein.NordoesTIwarrantorrepresentthatanylicense,eitherexpressorimplied,isgrantedunderanypatentright,copyright,maskworkright,orotherintellectualpropertyrightofTIcoveringorrelatingtoanycombination,machine,orprocessinwhichsuchsemiconductorproductsorservicesmightbeorareused.Copyright©1997,TexasInstrumentsIncorporated3AbstractThisdocumentpresentsasolutiontocontrolapermanentmagnetsynchronousmotorusingtheTMS320C24x.ThisnewfamilyofDSPsenablescost-effectivedesignofintelligentcontrollersforbrushlessmotorswhichcanfulfillenhancedoperations,consistingoffewersystemcomponents,lowersystemcostandincreasedperformances.Thecontrolmethodpresentedreliesonthefieldorientatedcontrol(F.O.C.).Thisalgorithmmaintainsefficiencyinawiderangeofspeedsandtakesintoconsiderationtorquechangeswithtransientphasesbycontrollingthefluxdirectlyfromtherotorcoordinates.Withinthisreportdifferentenhancedalgorithmsarepresented.Amongthesolutionsproposedarewaystosuppressphasecurrentsensorsandusingaslidingmodeobserverforspeedsensorlesscontrol.45TableofContents1.Introduction....................................................................................................................................72.TheDSPinmotorcontrol..............................................................................................................72.1Motorcontroltrend..................................................................................................................72.2BenefitsoftheDSPcontrollers................................................................................................82.3Alargerangeofapplications...................................................................................................93.TheTMS320C24xfamily...............................................................................................................94.TheSynchronousmotor...............................................................................................................114.1Electricmotors.......................................................................................................................114.2Thepermanent-magnetmotortechnology..............................................................................115.Enhancedmotorcontrol..............................................................................................................135.1Avectorcontrolmethod.........................................................................................................135.2TheFOCprinciple.................................................................................................................145.3SpaceVectorModulation.......................................................................................................165.4Fieldweakeningathighspeedswithclosedloopscheme......................................................195.5MaximumDCbusvoltageoftheinvertercontrol..................................................................206.Sensorandsensorlessalgorithms................................................................................................216.1Currentremotemeasurementandcalculation.......................................................................216.2Usingaspeedsensor..............................................................................................................236.3SensorlesscontrolledPMSMDrive..................................