TI-MotorControlCompendium-2010.ppt
- 文档编号:1143549
- 上传时间:2022-10-17
- 格式:PPT
- 页数:221
- 大小:48.84MB
TI-MotorControlCompendium-2010.ppt
《TI-MotorControlCompendium-2010.ppt》由会员分享,可在线阅读,更多相关《TI-MotorControlCompendium-2010.ppt(221页珍藏版)》请在冰豆网上搜索。
“Absolutelyamazing!
IwishIhadatoollikethiswhenIwaslearningaboutmotors.Fivestars!
”,Navigatingthecomplexitiesofmotorcontrol,-NikolaTeslaInventoroftheACInductionMotor,2010-2011,MotorControlCompendium,ByDaveWilsonTIMCUApplicationManagerforMotorControl,CopyrightTexasInstruments2011,MotorGlossary,Flux,isflux,inWebers,Inthemid1800sMichaelFaradayspeculatedthatmagneticfieldsexistaslinesofforce,whichwetodayrefertoas“magneticflux”,whichismeasuredinunitsof“Webers”.Essentially,themorefluxthereis,thestrongerthemagnetwillbe.Weconventionallythinkoffluxleavingthenorthpole,andre-enteringthesouthpoleofamagnet,asshownbythearrowsinthediagram.Ifwemeasurehowmuchfluxcutsthroughasurfaceareawhichisperpendiculartothefluxpath,thenwehaveameasureofthefluxdensityatthatparticularspotinspace.OneWeberoffluxcuttingthroughonesquaremeterofareaconstitutesafluxdensityofone“TESLA”,namedaftertheSerbianengineer,NikolaTesla,whoisALSOtheinventoroftheACinductionmotor.,MotorGlossary,Right-handRule,current,field,force,In1820,HansChristianOersteddiscoveredthatcurrentflowinginawirecreatesitsownmagneticfield,andwhenthisfieldinteractswithasecondmagneticfield,theresultisaforceactingontheconductor.Thisforceisproportionaltotheamountofcurrentflowinginthewire,thestrengthofthesecondmagneticfield,andthelengthofwirethatisaffectedbythesecondmagneticfield.ThedirectionoftheforcecanbedeterminedbyatechniqueknowastheRight-handRule.Ifyourrighthandisconfiguredasshownbelow,whereyourthumbpointsinthedirectionofpositivecurrentflow,andyourindexfingerpointsinthedirectionofthesecondmagneticfieldsflux(i.e.,flowingfromtheNorthpoletotheSouthpole),thenyourmiddlefingerwillbepointinginthedirectionoftheforceactingonthewire.,MotorGlossary,Left-handRule,S,N,DirectionofMotion,Awiremovinginamagneticfieldwillgenerateavoltageacrossitwhosemagnitudeisproportionaltohowmanyfluxlinesarecutbythewirepersecond.Thepolarityofthisback-EMFvoltagecanbedeterminedbytheLeft-handRule.Ifyouhandisconfiguredasshownbelowwhereyourindexfingerispointinginthedirectionofthemagneticflux(pointingtowardstheSouthpole),andyourmiddlefingerispointinginthedirectionofmotion,thenyourthumbwillbepointingtowardsthepositiveendofthewire.,MotorGlossary,Torque,Clockwisetorque=r1F1+r2F2-r3F3,Torquehasunitsofdistancetimesforce,i.e.,foot-poundsornewton-meters.,Thesumofalloftheperpendicularmagneticforcesactingonarigidbody(suchastherotorofamotor),timestheradiusesatwhichtheseforcesareapplied,resultsintorque.Pancakemotorsachievehightorquebymaximizingtheradiusatwhichtheforcesareappliedtotherotor.Ontheotherhand,longermotorswithsmallerradiusescanachievethesametorquebymaximizingtheforcethatisapplied.Thistrade-offallowsamotorcustomertoselectfromawiderangeofmotorformfactorstomeettheirspaceconstraints,andstillhavegoodtorqueperformance.UsingtheRight-handRule,weseethataforceisexertedonawirewhichiscarryingcurrentinamagneticfield.Thisforceisproportionaltotheamountofcurrentflowinginthewire,thestrengthofthemagneticfield,andthelengthofwirethatisaffectedbythemagneticfield.Inmostmotortopologies,thestrengthofthemagneticfieldandthewirelengthsexposedtothemagneticfieldarefixedasafunctionofthemotordesign.Thecurrenthoweverisadjustable.Sowecancombinetheeffectsofthemagneticfieldstrengthandthewirelengthsintoonetermcalledthetorqueconstant.Thisterm,whenmultipliedbythemotorcurrentresultsinmotortorque.Soweseethatinordertocontrolmotortorque,wemustcontrolmotorcurrent.,MotorGlossary,TorqueComponents,Thetorqueproducedbyamotorcanbedividedintotwodifferentcategories.Thefirstoneiscalledreactiontorqueoralignmenttorque.Thisaccountsforthetorquecreatedbythereactionbetweenthemagnetsontherotorandstator.Allmotorswiththeexceptionoftheswitchedreluctancemotorexhibitreactiontorque.Alesserknowntorquecomponentiscalledreluctancetorque.Thistorqueisgeneratedasaresultofamagneticfieldtryingtominimizethereluctanceofitsfluxpath.Forexample,ifyouplaceakitchenknifeonacountertop,andapproachoneendoftheknifewithamagnet,theknifewillmovetowardthemagnetinordertominimizethepathofthemagneticfield,eventhoughtheknifeitselfisnotmagnetized.Sincetheswitchedreluctancemotordoesnotuseamagnetoranelectromagnetontherotor,reluctancetorqueisitsonlytorquecomponent.Bothofthesetorquecomponentsareafunctionofthealignmentbetweentherotorandstator.ConsiderforexampleFigureA,wheretherot
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- TI MotorControlCompendium 2010