轨道交通车辆专业英语课件：Constructure of AC Electric Locomotive

ConstructureofACElectricLocomotiveRailwayVehicleEnglishPart1:ReadingMaterialFig.2-3PartsofanACelectriclocomotivePart1:ReadingMaterialTheFig.2-3showsanACelectriclocomotive,i.e.,alocomotivecollectingACpowerfromanoverheadline.Thecurrentpassesdirectlyfromthepantograph(orshoe)tothemainandauxiliaryinverters.Part1:ReadingMaterial1.ElectronicControls

Almosteverypartofthemodernlocomotive’sequipmenthassomeformofelectroniccontrol.Theyareusuallycollectedinacontrolcubiclenearthecabforeasyaccess.Thecontrolswillusuallyincludeamaintenancemanagementsystemofsomesortwhichcanbeusedtodownloaddatatoaportableorhand-heldcomputer.2.Pinion/Gear

Thetractionmotordrivestheaxlethroughareductiongearofarangebetween3to1(freight)and4to1(passenger).Part1:ReadingMaterial3.AsynchronousMotor

ModerntractionmotortypeusethreephaseACelectricalsupplyandnowthefavoureddesignformoderntraintractionsystemscanbeusedonDCandACelectrifiedrailwayswithsuitablecontrolelectronicsandonelectriclocomotives.4.AxleBrush

Themeansbywhichthepowersupplycircuitiscompletedwiththesubstationoncepowerhasbeendrawnonthelocomotive.Currentcollectedfromtheoverheadlineorthirdrailisreturnedviatheaxlebrushandoneoftherunningrails.Part1:ReadingMaterial5.Battery

Alltrainsareprovidedwithabatterytoprovidestart-upcurrentandforsupplyingessentialcircuits,suchasemergencylighting,whenthelinesupplyfails.ThebatteryisusuallyconnectedacrosstheDCcontrolsupplycircuit.6.CircuitBreaker

Anelectrictrainisalmostalwaysprovidedwithsomesortofcircuitbreakertoisolatethepowersupplywhenthereisafault,orformaintenance.OnACsystemstheyareusuallyontheroofnearthepantograph.Therearetwotypes—theairblastcircuitbreakerandthevacuumcircuitbreakerorVCB.Theairorvacuumpartisusedtoextinguishtheairwhichoccursasthetwotipsofthecircuitbreakerareopened.Part1:ReadingMaterial7.Converter

Generictermforanysolidstateelectronicsystemforconvertingalternatingcurrenttodirectcurrentorviceversaisconverter.WhereanACsupplyhastobeconvertedtoDCitiscalledarectifierandwhereDCisconvertedtoACitiscalledaninverter.ThewordoriginatedintheUSbutisnowcommonelsewhere.8.CoolingFansTokeepthethyristorsandotherelectronicpowersystemscool,theinteriorofamodernlocomotiveisequippedwithanairmanagementsystem,electronicallycontrolledtokeepallsystemsoperatingatthecorrecttemperature.Thefansarepoweredbyanauxiliaryinverterproducing3-phaseACatabout400V.Part1:ReadingMaterial9.DCLinkUsedonmodemelectronicpowersystemsbetweenthesinglephaserectifierandthe3-phaseinverter,itiseasiertoconvertthesinglephaseACfromtheoverheadlinetothe3-phaserequiredforthemotorsbyrectifyingittoDCandtheninvertingtheDCto3-phaseAC.10.Inverter

Electronicpowerdevicemountedontrainstoprovidealternatingcurrentfromdirectcurrent.PopularnowadaysforDCrailwaystoallowthree-phasedriveorforauxiliarysupplieswhichneedanACsupply.Part1:ReadingMaterial11.LineBreaker

Electro-mechanicalswitchinatractionmotorpowercircuitisusedtoactivateordisablethecircuit.Itisnormallyclosedtostartthetrainandremainsclosedallthetimepowerisrequired.Itisopenedbyacommandfromthedrivingcontroller,no-voltsdetected,overloaddetectedand(wererequired)wheelspinorslidedetected.Itislinkedtotheoverloadandno-voltcontrolcircuitssothatitfunctionsasaprotectivecircuitbreaker.12.MasterController

Driver'spowercontroldeviceislocatedinthecab.Thedrivermovesthehandleofthemastercontrollertoapplyorreducepowertothelocomotiveortrain.Part1:ReadingMaterial13.MotorBlowers

Tractionmotorsonelectriclocomotivesgetveryhotand,tokeeptheirtemperatureatareasonablelevelforlongperiodsofhardwork,theyareusuallyfittedwithelectricfanscalledmotorblowers.Onamodernlocomotive,theyarepoweredbyanauxiliary3-phaseACsupplyofaround400Vsuppliedbyanauxiliaryinverter.14.Rectifier

AconverterconsistingofthyristorsanddiodesisusedtoconvertACtoDC.Amodernlocomotivewillusuallyhaveatleasttwo,oneforthepowercircuitsandoneormorefortheauxiliarycircuits.Part1:ReadingMaterial16.SandBox

Locomotivesalwayscarrysandtoassistadhesioninbadrailconditions,andisoftenprovidedonmultipleunittraintoo.17.SynchronousMotor

Tractionmotorwherethefieldcoilsaremountedonthedriveshaftandthearmaturecoilsinthehousing,theinverseofnormalpractice.Thisisasingle-phasemachinecontrolledbysimpleinverter.Nowsupersededbytheasynchronousmotor.Part1:ReadingMaterial18.Transformer

Asetofwindingswithamagneticcoreisusedtostepdownorstepupavoltagefromoneleveltoanother.Thevoltagedifferencesaredeterminedbytheproportionofwindingsontheinputsidecomparedwiththeproportionontheoutputside.AnessentialrequirementforlocomotivesandtrainsusingACpower,wherethelinevoltagehastobesteppeddownbeforeusedonthetrain.19.Pantographs

Currentiscollectedfromoverheadlinesbypantographs,asshowninFig.2-4.Pantographsareeasyintermsofisolation—youjustlowerthepantolosethepowersupplytothevehicle.However,itiscomplicatedtooperate.Part1:ReadingMaterial

Sincethepantographisusuallythesinglepointpowercontactforthelocomotiveorpowercar,itmustmaintaingoodcontactunderallrunningconditions.Thehigherthespeed,themoredifficultthemaintenanceofgoodcontact.Wehavealreadymentionedtheproblem(above)ofawavebeingformedinthewirebyapantographmovingathighspeed.Fig.2-4PantographPart1:ReadingMaterialPantographcontactismaintainedeitherbyspringorairpressure.Compressedairpressureispreferredforhigh-speedoperation.Thepantographisconnectedtoapistoninacylinderandairpressureinthecylindermaintainsthepantographintheraisedcondition.RailwayVehicleEnglishPart2：VocabularyPart2:Vocabularythyristor半导体闸流管sandbox砂箱transformer变压器axlebrush轴刷pantograph受电弓vacuumcircuitbreaker(VCB)真空断路器asynchronousmotor异步电动机auxiliaryinverter逆变器electroniccontrol电气控制Part3:CommentariesforLongDifficultSentencesRailwayVehicleEnglishPart3:CommentariesforLongDifficultSentences123Currentcollectedfromtheoverheadlineorthirdrailisreturnedviatheaxlebrushandoneoftherunningrails.

从架空线路或第三轨道收集的电流通过轴刷和其中一个运行轨道返回。Tractionmotorwherethefieldcoilsaremountedonthedriveshaftandthearmaturecoilsinthehousing,theinverseofnormalpractice.

牵引电机的磁场线圈安装在传动轴上，电枢线圈安装在外壳上，这与正常的做法相反。Tokeepthethyristorsandotherelectronicpowersystemscool,theinteriorofamodernlocomotiveisequippedwithanairmanagementsystem,electronicallycontrolledtokeepallsystemsoperatingatthecorrecttemperature.为了保持晶闸管和其他电子电力系统的冷却，现代机车的内部配备了空气管理系统，由电子控制，以保持所有系统在正确的温度下运行。Part3:CommentariesforLongDifficultSentences45Theaircompressorisrequiredtoprovideaconstantsupplyofcompressedairforthelocomotiveandtrainbrakes.空气压缩机需要为机车和列车的制动器提供持续的压缩空气供应。

Sincethepantographisusuallythesinglepointpowercontactforthelocomotiveorpowercar,itmustmaintaingoodcontactunderallrunningconditions.由于受电弓通常是机车或动力车的单点电源接触点，因此在所有运行条件下都必须保持良好的接触RailwayVehicleEnglishPart4:ExerciseandActivityPart4:ExerciseandActivityDirections：Explainthemeaningsandfunctionsofthefollow