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1、英文原文INDUCTIONMOTORSTARTINGMETHODSANDISSUESAbstract-ManymethodscanbeusedtostartlargeACinductionmotors.Choicessuchasfullvoltage,reducedvoltageeitherbyautotransformerorWyes-Delta,asoftstarter,orusageofanadjustablespeeddrivecanallhavepotentialadvantagesandtradeoffs.Reducedvoltagestartingcanlow
2、erthestartingtorqueandhelppreventdamagetotheload.Additionally,powerfactorcorrectioncapacitorscanbeusedtoreducethecurrent,butcaremustbetakentosizethemproperly.Usageofthewrongcapacitorscanleadtosignificantdamage.Choosingtheproperstartingmethodforamotorwillincludeananalysisofthepowersystemasw
3、ellasthestartingloadtoensurethatthemotorisdesignedtodelivertheneededperformancewhileminimizingitscost.Thispaperwillexaminethemostcommonstartingmethodsandtheirrecommendedapplications.IndexTerms:motorstarting.Reducedvoltagestartautotransformer,wyes-delta,powerfactorcorrectionI.INTRODUCTIONTh
4、ereareseveralgeneralmethodsofstartinginductionmotors:fullvoltage,reducedvoltage,wyes-delta,andpartwindingtypes.Thereducedvoltagetypecanincludesolidstatestarters,adjustablefrequencydrives,andautotransformers.These,alongwiththefullvoltage,oracrossthelinestarting,givethepurchaseralargevariety
5、ofautomotiveswhenitcomestospecifyingthemotortobeusedinagivenapplication.Eachmethodhasitsownbenefits,aswellasperformancetradeoffs.Properselectionwillinvolveathoroughinvestigationofanypowersystemconstraints,theloadtobeacceleratedandtheoverallcostoftheequipment.Inorderfortheloadtobeaccelerate
6、d,themotormustgenerategreatertorquethantheloadrequirement.Ingeneraltherearethreepointsofinterestonthemotor'sspeed-torquecurve.Thefirstislocked-rotortorque(LRT)whichistheminimumtorquewhichthemotorwilldevelopatrestforallangularpositionsoftherotor.Thesecondispull-uptorque(PUT)whichisdefinedas
7、theminimumtorquedevelopedbythemotorduringtheperiodofaccelerationfromresttothespeedatwhichbreakdowntorqueoccurs.Thelastisthebreakdowntorque(BDT)whichisdefinedasthemaximumtorquewhichthemotorwilldevelop.Ifanyofthesepointsarebelowtherequiredloadcurve,thenthemotorw