电气工程及其自动化专业英语ppt课件.ppt

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1、电气工程及其自动化专业英语SpecializedEnglishforElectricalEngineering＆ItsAutomation戴文进主编杨植新副主编Part2ElectricMachineryUnit11TheTransformeronNoLoadUnit13ConstructionandApplicationofD.C.MachinesUnit16Three-PhaseInduction(Asynchronous)MachinewiththeRotoratStandstill·Unit19ArmatureReactionofSalient-PoleSync

2、hronousMachineaTwo-ReactionTheoryUnit11TheTransformeronNoLoad-SpecializedEnglishWordsincloseproximity(to)紧密耦合permeability磁导率magnetizingcurrent激磁电流powercomponentofcurrent电流的有功分量sinusoidalvariations正弦变量amutuallyinducede.m.f.互感电动势theappliedvoltage外施电压zero-power-factor零功率因数theno-loadpowerfa

3、ctor空载功率因数formulate用公式表示,系统地阐述saturation饱和Unit11TheTransformeronNoLoadTheSimpleTwo-CoilTransformerThetransformerisastraightforwardapplicationofFaraday'sLawofElectromagneticInduction.Thesimpletransformerconsistsoftwocoilsincloseproximity.OnecoilofN1turnsisexcitedwithalternatingcurrentandt

4、hereforeestablishesafluxφ11whichalternateswiththecurrent(随时间交变）.Theothercoilislinkedby（与---交链）mostofthisfluxandthushasamutuallyinducede.m.f.ofvaluee2=－N2dφ21/dt.Thise.m.f.woulddrivealoadcurrentthroughanycircuitconnectedtotheterminalsofthesecondcoil.Energywouldthenbetransferredthroughthem

5、ediumofthemagneticfield（磁场媒介）fromcoil1tocoil2.Thetransformationcouldbefromanyconvenientinputvoltagetoanyconvenientoutputvoltage.Thisapparentlysimplefunctionofthetransformermakesitasvitaltomodernindustryasthegeartrainwhich,asa“transformer”ofspeedandtorquerepresentsaninterestinganalogy（句子的

6、主语是“function”，谓语为“make”，“asvital…as”意为“与……一样重要”，“which”引导一个定语从句“whichrepresentsaninterestinganalogyasa‘transformer’ofspeedandtorque”，修饰“geartrain”，意为“齿轮箱与变压器表现出一种有趣的相似，齿轮箱被称为速度和转矩的‘变换器’。”Thecoilswouldbeonanironcore(铁芯）andsoatthecostofintroducingironlosses,thevalueoffluxperampereisincreas

7、edseveralhundredtimesbecauseofthechangeofpermeabilityfromμ0toμ0μr.Theexcitingormagnetizingcurrent（励磁电流）canthusbeverysmall.Further,theproportionofthetotalfluxwhichislinkedmutuallybythetwocoilsisgreatlyincreased.Lookedatanotherway,theleakagefluxΦ1whichlinksN1turnsaloneand