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ID:50322224
大小:8.23 MB
页数:138页
时间:2020-03-08
《Electric Machinery 电机学 英汉双语 教学课件 作者 刘慧娟 英文课件Chapter1-DC machine.ppt》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、Chapter1DCMachines1.1Introductiontodcmachines1.2Armaturewindings1.3Magneticfieldsofdcmachines1.4Inducedvoltageandelectromagnetictorque1.5Equivalentcircuitofadcmachine1.6Powerflowandlossesindcmachine1.7Operationcharacteristicsofdcgenerator1.8Operationcharacteristicsofdcmotors1
2、.9Speedcontrolofshuntdcmotor1.10Startingofdcmotor1.11Brakingofdcmotor1.12CommutationBriefContent1.1.1TheConstructionofDCMachinesDCMachine(Armaturecore)(Armaturewinding)(Brushes)(Brushes)(Commutator)(Shaft)FieldpoleFieldwindingThecross-sectionofadcmachine(interpole)(Fieldpole)
3、(York)(Armaturecore)(Armaturewinding)(Frame)FieldwindingSheetofrotorStatorandRotorAirgapwhichisseparatingstatorandrotorStationarypart:Frame,FieldPoleandBrushesRotatingpart:Armaturecore,WindingShaftandCommutatorDCMachinesThearmaturewindingisplacedintherotorslotandconnectedtoro
4、tatingcommutatorwhichrectifiestheinducedvoltageThebrusheswhichareconnectedtothearmaturewinding,rideoncommutator1.1.2OperationPrincipleofDCMachines(sliprings)(brushes)(commutator)(brushes)DCMotors:operationprinciplesSupplyaDCvoltagetothebrushesXandY.1.1.3ExcitationtypesofDCMac
5、hinesSeparatelyexcitedDCmachineShunt(excited)DCmachineSeries(excited)DCmachineCompounded(excited)DCmachineDCMotor+-+-+-他励(Separatelyexcited)+-并励(Shuntexcited)+_串励(Seriesexcited)复励(Compoundexcited)-+-++-他励(Separatelyexcited)-+并励(Shuntexcited)-+串励(Seriesexcited)复励(Compoundexcit
6、ed)DCGenerator1、Ratedpower:W,kWMotor:theoutputmechanicalpower:Generator:theoutputelectricalpower:2、Ratedcurrent:A3、Ratedvoltage:V4、Ratedspeed:r/min5、Ratedexcitationcurrent:A6、Ratedexcitationvoltage:V8、Polenumber:polepairnumber1.1.4RatingsofdcmachinesExample1-1Adcgenerator,its
7、ratedpowerPN=10kW,ratedvoltageUN=230V,ratedspeednN=2850r/min,ratedefficiencyN=0.85.Calculateitsratedcurrentanditsratedinputpower?Solution:theratedcurrentofthedcgeneratorisIN=PN/UN=10*1000/230=43.48(A);TheratedinputpowerisP1=PN/N=10*1000/0.85=11765(W).Example1-2Adcmotor,itsr
8、atedpowerPN=17kW,ratedvoltageUN=220V,ratedspeednN=1500r/min,ratedeff
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