Excitation研发培训,设计培训

SynchronousMachines-

ExcitationContinuedLossesandEfficiencyMarkFanslowTecoWestinghouseEngineeringTrainingDec.2005第一页，共八十二页。Outline Formulaforcalculatingthemagneticcircuitgeometryofasynchronousmachine(SMDS)Calculatefluxdensityandampere-turnsofmagneticcircuitConstructtheopencircuitandsynchronousimpedancecurvesShortCircuitRatio(SCR)CalculateFieldExcitationRequiredforgivenloadandPFEfficiency第二页，共八十二页。MagneticCircuitSMDSAreaofGapAgap=AreaofAirGapinsquarecentimetersCp=PoleConstantCL=GrossCoreLengthInchesSOD=StatorOuterDiameterInchesPoles=NumberofPoles6.45=conversionfactor2.542NOTE:TheuserentersSODandCLintoSMDSininchesbutSMDSprintoutlistsmagneticpathareasandlengthsinsquarecentimetersandcentimeters第三页，共八十二页。SMDSOutput第四页，共八十二页。MagneticCircuitCont.Areaofstatorcore第五页，共八十二页。MagneticCircuitCont.Acore: AreaofstatorcoreinsquarecentimetersCLN: NetCoreLength(inches)DSC: DepthofstatorCore(inches)SID: StatorInnerDiameter(inches)Dss: DepthofStatorSlot(inches)#vents:NumberofstatorventsVWth Widthofstatorvent(inches)WS: WidthofstatorslotNotethatSMDSasksforthewidthofthestatorslotatthreedepthsintheslotWS1,WS2,WS3,thisistoaccommodaterandomwoundstatorswithnon-rectangularslots.ForstandardrectangularslotsWS1=WS2=WS3=WS第六页，共八十二页。MagneticCircuitCont.TeethWidthAreaTooth第七页，共八十二页。MagneticCircuitCont.AreaofPoleWpole=Widthofpolebody(inches)CL=GrossrotorLength.98=Stackingfactorrotorpunchings第八页，共八十二页。MagneticCircuitCont.Ltooth=Dssx2.54Lpole=lengthofpolebodyx2.54LGap=GminxKGx2.54KG=GapFactor(sameasinductionmotor)第九页，共八十二页。MagneticCircuitCont.tNL=TotalMagneticFluxNo-LoadE=LinetoLineVoltageFreq=FrequencyKw=WindingFactorZph=TotalSeriesConductorsperphase第十页，共八十二页。MagneticCircuit第十一页，共八十二页。MagneticCircuitCont.B-Hcurvesforthestatorelectricalsteelwilldeterminethenumberofampereturnsrequiredtopushthefluxdensitythroughthefluxpathsofthestator.ATcore=Ampere-turnsrequiredtomagnetizestatorcoreATteeth=Ampere-turnsrequiredtomagnetizestatorteeth第十二页，共八十二页。TOPICSHIFT-PoleLeakageBeforecalculatingthefluxdensityofthepole,theleakagefluxpathshavetobeconsidered.第十三页，共八十二页。PoleLeakageFluxThefluxrequiredatthepolefaceisthefluxthatlinkstheair-gapandstatormagneticcircuits().Becauseofpoleleakageflux,thefluxrequiredatthetopofthepolebodyisthesumofthepoleshoeleakageflux+SLThefluxrequiredatthebottomofthepoleshoeisthen+SL+BL第十四页，共八十二页。PoleLeakageFluxRecallthatinamagneticcircuit,Flux=mmfxmagneticpermeanceLeakagefluxbetweenpolesisequaltothemmfperpolexthemagneticpermeanceofthespacebetweenpoles.Recallthatmagneticpermeanceofairis:第十五页，共八十二页。PoleLeakageFluxToevaluatethetotalleakagefluxofthepole,theleakagefluxwillbebrokeninto6leakagepaths:PoleBodytoBodyLeakagePoleBodyEndtoBodyEndLeakagePoleShoeUndersidetopoleshoeundersidePoleShoeTiptoShoePoleTipPoleShoeEndSphericalQuadrantPoleShoeEndtoPoleShoeEnd第十六页，共八十二页。PoleLeakageFlux第十七页，共八十二页。PoleBodyLeakage第十八页，共八十二页。PoleBodySideLeakageAreaoffluxtubeδxLengthofFluxtubeIfMistheampereturnsperpole,itisassumedtheleakagemmfvarieslinearlyalongthelengthofthepolebody.Thenatthepolebottomthemmfiszeroandatthepolebodytopthemmfis2.52MM=ATgap+ATcore+ATteeth第十九页，共八十二页。PoleBodySideLeakageFluxThefluxofasinglefluxtube第二十页，共八十二页。PoleBodySideFluxTheintegrationresultedinatotalleakagefluxperunitofcorelength.TheresultoftheintegrationismultipliedbypolelengthCltodeterminetotalbodyleakageflux.第二十一页，共八十二页。PoleBodyEndLeakageFigure4EN132第二十二页，共八十二页。PoleBodyEndLeakageFluxPermeanceofonetubeofflux第二十三页，共八十二页。PolebodyendleakagefluxThemmfvariesfrom0aty=0to2.52Maty=Landhasavalueof2.52xMx(y/L)foratubeofflux第二十四页，共八十二页。Polebodyendleakageflux=Leak2第二十五页，共八十二页。TotalPoleBodyLeakageIfyouaddtheprevioustwoequationstogether,theresultcanbewrittenasMxborLeak1+Leak2=M(b)=LeakBodySMDSprintsoutPoleLeakage“BodyEnd”and“BodySide”.BodySide=Leak1/M;BodyEnd=Leak2/M第二十六页，共八十二页。SMDSOutput第二十七页，共八十二页。InsideSurfaceofPoleLeakageFigure5fromengineeringnote132第二十八页，共八十二页。PoleShoeLeakageElementarypermeanceSurfaceBmmf=constant2.52Moverheightg第二十九页，共八十二页。ShoeLeakageCont..TotalleakagefluxperunitlengthSurfaceB第三十页，共八十二页。ShoeLeakageCont.TotalshoeleakageoverlengthofPoleClSurfaceBUsingthesamelogicforsurfaceC:第三十一页，共八十二页。EndLeakageSphericalQuadrantLeak5=2x2x2.52Mx.077αα=polepitch第三十二页，共八十二页。PoleShoeEndLeakageFluxFigure8Usingsimilarmethodologyasdoneforothersurfaces第三十三页，共八十二页。PoleShoeEndLeakageFlux=Leak6第三十四页，共八十二页。TotalPoleShoeLeakageLeakshoe=Leak3+Leak4+Leak5+Leak6SMDSprintout:PoleLeakage“ShoeEnd”and“ShoeSide”ShoeSide=(Leak3+leak4)/MShoeEnd=(Leak5+Leak6)/M第三十五页，共八十二页。SMDSOutput第三十六页，共八十二页。FinishMagneticCircuitsFluxinthepolehastoequalthefluxcrossingtheairgapplustheleakagefluxinthefieldcircuit.Thedifferencebetweentheairgapfluxandairgapfluxplusleakagefluxisaveragedoverthelengthofthepolecircuit.第三十七页，共八十二页。MagneticCircuitsCont.LS=Leakshoe

T=(Leakshoe+Leakbody)

LS:Leakageofpoleshoe

T:TotalLeakageofPole

PT=

tNL+

LS:FluxattopofPoleBody

PB=

tNL+

T:FluxatbottomofPoleBody

第三十八页，共八十二页。MagneticCircuitCont.BpoleT=

PT/Apole=FluxDensitytopofpolebodyBpoleB=

PB/Apole=FluxDensitybottomofpolebodyBpole=BpoleB–2(BpoleB–BpoleT)Byoke=

PB/AyokeATpoleandATyokecanbereadfromtheB-Hcurveforthesteelusedineach第三十九页，共八十二页。OpenCircuitSaturationCurveThepreviousequationsusedtheratedvoltageofthemachinetocalculatetotalflux.IftheVoltageisvariedfrom.25Vto1.5V,valuesofATcanbedeterminedateachvoltagepointandtheopencircuitsaturationcurvecanbecalculated.第四十页，共八十二页。OpenCircuitSaturationCurve第四十一页，共八十二页。AmpereTurnsofArmatureReactionRecallthatarmaturereactionistheeffectthatthearmaturemmfhasondistortionoftheopencircuitno-loadmmfproducedbythefieldactingalone.ArmatureReactioncanbemodeledbyaddinganimpedanceinphasewiththearmatureleakagereactance.Additionalampere-turnsneedtobegeneratedbythefieldtoovercometheeffectsofarmaturereaction第四十二页，共八十二页。Ampere-TurnsofArmatureReactionα: PoleEmbracePH: NumberofphasesSPP: SlotsperpoleperphaseTPC: TurnspercoilofarmatureCRTS: NumberofarmaturecircuitsAmps: RatedampsofmachineKW: Windingfactorofmachine第四十三页，共八十二页。OpenCircuitSaturationCurveDirectAxisSynchronousImpedanceArmaturecurrentAmpere-turnsperpolePUTerminalVoltageOpencircuitsatONominalFratedDBAIZaCAATNo-LoadampereturnsAirgaplineG第四十四页，共八十二页。ShortCircuitRatioTheShortCircuitRatio(SCR)isfromthepreviouscurveShortCircuitRatioisaimportantparameterinsynchronousmotordesign.Itmaybeconsideredtheratiooffieldstrengthtoarmaturestrength.第四十五页，共八十二页。SCRSCRLow:SmallairgapPoorvoltageregulation(generators)Smallamountoffieldcopper,aninexpensivefieldwindingLowPullOutTorque(Motors)SCRHigh Largeairgap goodvoltageregulation(generators) largeamountoffieldcopper,expensivefield winding第四十六页，共八十二页。ExcitationatAnyLoadandPFRecallthattheAirGapVoltageistheterminalvoltageplusthearmatureresistancedropandarmatureleakagereactancedropaddedasvectors.Thisvoltageisusedtocalculatethefluxdensityunderload(epct)IVIRIXLVgap第四十七页，共八十二页。OpenCircuitSaturationCurveDirectAxisSynchronousImpedanceArmaturecurrentAmpere-turnsperpolePUTerminalVoltageNominalratedATPgATPsATPFSAirGapVoltage第四十八页，共八十二页。FieldExcitationCalculationATPgATPsATPFSLeadingPFATPgATPsATPFSTotalfieldexcitation

Totalfieldexcitation

UnityPF第四十九页，共八十二页。SMDSOutput第五十页，共八十二页。EfficiencyLossesofasynchronousMotorConsistof6categories:ArmatureI2RFieldI2RCoreFWStrayExciter第五十一页，共八十二页。ArmatureCopperLossesArmaturecopperloss:I2rated(Res)Whendoingthiscalculation,aninitialvalueofefficiencymustbeassumed,theequationsforefficiencyandRatedcurrentarethensolvediterativelytogetthefinalresults.Calculatearmatureresistanceatoperatingtemperature.第五十二页，共八十二页。FieldCopperLossUsingmethodsdescribedonpreviousslide,calculatethefullloadfieldcurrent.ThefieldcopperlossisthenI2R(ResF)CalculateResFatoperatingtemperature第五十三页，共八十二页。CoreLossCoreLossStatorTeethPt: Toothlossatno-loadinKWWt: Weightofstatorteeth第五十四页，共八十二页。CoreLossCont.Bt: Fluxdensityinmiddleoftoothkilolines/inches2β: Exponentdependantongradeofsteel,3.0forstandard 10502FHsteelKi: 1.3forcircularstatorlaminationsKi: 1.64forMultiSegmentLaminations,brackettypeconstruction.Ki: 1.7forMultiSegmentLaminationuptoand including20polesKi: 1.9forMultiSegmentLaminationsabove22polesS1: NumberofstatorslotsCLN: Netcorelengthstator Kstk: Stackingfactorforstatorlaminationshs: Statorslotheightbt: Averagetoothwidth 第五十五页，共八十二页。CoreLoss-StatorSteelCoreLossstatorCorePc: CoreLossinKWWc: WeightofstatorcoreinLBSBc: Statorcorefluxdensityinkiloline/inches2第五十六页，共八十二页。CoreLoss-PoleFaceLossPoleFaceLoss:Polefacelossiscreatedbyeddycurrentsbeinginducedinthetopofthepoleshoe.Thesecanbereducedingeneralbyincreasingtheairgaporloweringthefluxdensityinthegap.Polefacelossisfoundbymultiplying6constantstogetherwiththenumberofpoles,poleembrace,andgrosscorelength.第五十七页，共八十二页。PoleFaceLossCont.Bg:GapFluxDensityS1:NumberofstatorslotsK6=2.6for.125inchthickpolelaminationsK6=1.2for0.63inchthickpolelaminations第五十八页，共八十二页。PoleFaceLossCont.W=WidthStatorSlotg=minairgap第五十九页，共八十二页。PoleFaceLossCont.s=Statorslotpitch第六十页，共八十二页。PoleFaceLossCont.CW=.39xC1第六十一页，共八十二页。DamperLossDamperLoss第六十二页，共八十二页。DamperLossCont.db: Damperbardiameter(inches)b1: Depthofpenetrationfordamperbaratslotharmonic frequencyb2: Depthofpenetrationfordamperbaratsecondslot harmonicfrequency: Damperbarresistivityinmicro-ohm-inchesq: Statorslotsperpoleperphasem: numberofphasesf: ratedfrequency第六十三页，共八十二页。DamperLossCont.hb2: Heightofslotabovedamperbarbb2: Widthofslotabovedamperbarg: Minimumsingleairgap第六十四页，共八十二页。DamperLossCont.b: DamperslotpitchatstatorborediameterKg: Carter’sairgapcoefficientWss: Widthofarmatureslotopening第六十五页，共八十二页。DamperLossCont.b: Damperslotpitchatstatorborediameters: StatorslotpitchatstatorborediameterWss: Widthofst