輪機(jī)英語77課件

MarineEngineeringEnglish《輪機(jī)英語》APracticalCourseforEngineersWorkingonBoardShips

MarineElectricalSystemandAutomatizationLesson26Marine

ElectricityDistributionSystem第26課船用電力分配系統(tǒng)LearningObjectives:1.Graspsomeusefulwordsandexpressionsinthewholetext.2.Afterstudyingthelesson,heorshewillhaveabetterunderstandingofMarine

ElectricityDistributionSystem.3

4part1

NewWordsandExpressions5part2

TextAnalysisL26ElectricityDistributionThecontrolanddistributionoftheelectricalenergygeneratedbygeneratorsareeffectedbypowerdistributionequipment,i.e.switchboards.#發(fā)電機(jī)產(chǎn)生的電能的控制和分配受配電設(shè)備(即配電盤)的影響。L26ElectricityDistributionSwitchboardsareeither(a)Mainswitchboards,(b)Emergencyswitchboards,(c)Sectionboards(orsub-boards),or(d)Distributionboards.#配電盤可以是(a)主配電盤、(b)應(yīng)急配電盤、(c)區(qū)域配電盤(或子配電盤)或(d)分配電盤。8

Introduction(Backgroundknowledge)

L26ElectricityDistributionAmainswitchboardconsistsofthegenerator

controlpanel,theloadpanelandthepaneloftheparalleloperationofthegenerator.#主配電盤由發(fā)電機(jī)控制屏、負(fù)荷屏和發(fā)電機(jī)并車屏組成。

Introduction(Backgroundknowledge)

Introduction(Backgroundknowledge)

Introduction(Backgroundknowledge)

L26ElectricityDistributionItsmainfunctionisto(1)switchonoroffthecurrentcircuitaccordingtotherequirement(manuallyorautomatically);其主要功能是(1)根據(jù)需要(手動(dòng)或自動(dòng))接通或斷開電流回路；L26ElectricityDistribution(2)maketheprotectiondeviceenergizetodisconnecttheelectricalequipmentwiththecircuit,givingthealarmsignalwhenthereissomethingwrongwiththeelectricalpowersupplysystem;使保護(hù)裝置通電，以斷開電氣設(shè)備與電路的連接，當(dāng)供電系統(tǒng)出現(xiàn)故障時(shí)發(fā)出報(bào)警信號(hào)；L26ElectricityDistribution(3)measureorindicateeveryelectricalparameterssuchasvoltage,current,watt,powerfactoretc.duringtheoperation;測量或指示運(yùn)行中的電壓、電流、瓦特、功率因數(shù)等各項(xiàng)電氣參數(shù)；L26ElectricityDistribution(4)adjustthedistributionofthepowerofthegeneratorinparalleloperationorthevoltage,frequencyofthepowerstation;調(diào)整并聯(lián)運(yùn)行發(fā)電機(jī)的功率分配或電站的電壓、頻率；L26ElectricityDistribution(5)indicatethesignaloftheconditionofthecurrentcircuit,theconditionofthebreakersandtheerrorfromthenormalworkingcondition.指示電流回路狀態(tài)信號(hào)、斷路器狀態(tài)和正常工作狀態(tài)的偏差。L26ElectricityDistributionThegeneratedsupplyisprovidedtoconductorsknownas“bus-bars”whicharelocatedbehindthemainswitchboard.#產(chǎn)生的電能提供給叫做“匯流排”的導(dǎo)體，它位于主配電盤的后面。L26ElectricityDistributionThesupplythenpassesthroughcircuitbreakerstoauxiliariesdirectlyortosectionordistributionboards.#電能則通過斷路器直接通向輔助設(shè)備，或者其它區(qū)域配電盤或分配電盤。L26ElectricityDistributionAcircuitbreakerisanisolatingswitch.#斷路器其實(shí)就是一個(gè)獨(dú)立的開關(guān)。L26ElectricityDistributionAsectionboardisagroupingofelectricalservicesfedfromthemainboard.#區(qū)域配電盤是由主配電盤供電的一組電氣設(shè)施。L26ElectricityDistributionAdistributionboardfeedsminorsuppliessuchaslightingandmayitselfbefedfromthemainboardorasectionboard.#分配電盤供給小的電力，比如照明，并且可能自身由主配電盤或區(qū)域板供電。L26ElectricityDistributionAnACdistributionsystemisprovidedfromthemainswitchboardwhichisitselfsuppliedbythealternators.#交流電配電系統(tǒng)的電是由主電板分配的，交流發(fā)電機(jī)直接向主配電盤供電。L26ElectricityDistributionThevoltageattheswitchboardisusually415butonsomelargeinstallationsitmaybeashighas3,300.#主配電盤上的電壓一般為415伏，但在一些大型的設(shè)備上，電壓有可能達(dá)到3300伏。L26ElectricityDistributionPowerissuppliedthroughcircuitbreakerstolargerauxiliariesatthehighvoltage.#它通常在高壓狀態(tài)下，通過斷路器向大型輔助設(shè)置上輸出功率。L26ElectricityDistributionSmallerequipmentmaybesuppliedviafusesorminiaturecircuitbreakers.#而小型的設(shè)備則可以用熔斷器(保險(xiǎn)絲)或者微型斷路器。L26ElectricityDistributionLowervoltagesuppliesused,forinstance,forlightingat220volts,aresuppliedbystepdowntransformersinthedistributionnetwork.#例如，用于220伏照明的低壓供電，可以在分電網(wǎng)中由降壓變壓器來供電。L26ElectricityDistributionThedistributionsystemwillbethreewireswithinsulatedorearthedneutral.#配電系統(tǒng)是三線(相)絕緣或者中線接地。L26ElectricityDistributionTheinsulatedearthhaslargelybeenfavoredbutearthedneutralsystemshaveoccasionallybeeninstalled.#大多數(shù)使用的是三線絕緣的配電系統(tǒng)，中心接地的系統(tǒng)有時(shí)也會(huì)使用。L26ElectricityDistributionTheinsulatedearthsystemcansufferfromsurgesofhighvoltageasaresultofswitchingorsystemfaultswhichcoulddamagemachinery.#由于斷開與閉合或者可能損壞機(jī)器的系統(tǒng)故障，三相絕緣系統(tǒng)可能遭受高壓電涌。L26ElectricityDistributionUseoftheearthedsystemcouldresultinthelossofanessentialservicesuchasthesteeringgearasaresultofanearthfault.#接地系統(tǒng)的使用可能導(dǎo)致一項(xiàng)重要的用途，比如舵機(jī)，由于接地故障而喪失。L26ElectricityDistributionAnearthfaultontheinsulatedsystemwouldnothoweverbreakthesupplyandwouldbedetectedintheearthlampdisplay.#然而，絕緣系統(tǒng)中的一個(gè)接地故障不會(huì)導(dǎo)致供電中斷，同時(shí)能夠在接地指示燈上顯示出來。L26ElectricityDistributionInsulatedsystemshavethereforebeengivenpreferencesinceearthfaultsareacommonoccurrenceonshipsandalossofsupplyinsuchsituationscannotbeaccepted.#由于接地故障在船上普遍發(fā)生，并且在這些情況下供電中斷不能被接受，因此，(三相)絕緣系統(tǒng)得以青睞。L26ElectricityDistributionInthedistributionsystemtherewillbecircuitbreakersandfuses.#配電系統(tǒng)中會(huì)有斷路器和保險(xiǎn)絲。L26ElectricityDistributionEquipmentforACsystemsishoweversmallerandlighterbecauseofthehighervoltageandthereforelowercurrents.#然而，交流系統(tǒng)中的電器設(shè)備較小和較輕，因?yàn)槠漭^高的電壓、較低電流。L26ElectricityDistributionMiniaturecircuitbreakersareusedforcurrentsuptoabout100A

andactasafuseandacircuitbreaker.#微型斷路器用于電流高達(dá)100A，起到保險(xiǎn)絲和斷路器的作用。L26ElectricityDistributionThedevicewillopenonoverloadandalsointheeventofashortcircuit.#這種設(shè)備會(huì)在過載和發(fā)生短路的情況下自動(dòng)斷開。L26ElectricityDistributionUnlikeafuse,thecircuitcanbequicklyremadebysimplyclosingtheswitch.#不同于熔斷器(保險(xiǎn)絲)，電路還能夠通過開關(guān)簡單的閉合來達(dá)到電路迅速的恢復(fù)。L26ElectricityDistributionAlargeversionofthisdeviceisknownasthemouldedcasecircuitbreakerandcanhandlecurrentsinexcessof1,000A.#這種形式的設(shè)備被稱為塑殼式斷路器，并且它能夠處理超過1000A的電流。L26ElectricityDistributionPreferentialtrippingandearthfaultindicationwillalso

beapartoftheACdistributionsystem.#優(yōu)先卸載和接地故障指示也是交流配電系統(tǒng)的一部分。L26ElectricityDistributionPreferentialtrippingisameansofretainingessentialelectricalsupplies.#優(yōu)先卸載是保持重要電力供應(yīng)的一種方法。L26ElectricityDistributionIntheeventthatageneratorcannotsupplyalltheloadthennon-essentialloadsaredisconnectedbypreferentialtrips.如果發(fā)電機(jī)不能向所有的負(fù)載供電，那么不重要的負(fù)載就被優(yōu)先卸載所斷開。L26ElectricityDistributionTheintentionistoreducethegeneratorloadwhileensuringessentialequipmentsuchassteeringgear,navigationlights;etc.retainsitselectricalsupply.#這樣的目的就是減少發(fā)電機(jī)所承受的負(fù)載來保證重要的設(shè)備，比如舵機(jī)、航行燈等等，保持其電力供應(yīng)。L26ElectricityDistributionEarthfaultsareusuallydetectedbytheuseof

earthindicatinglamps.#可以使用接地故障指示燈來檢測接地故障。L26ElectricityDistributionTwolampsareused,eachratedforthefullsystemvoltage,butconnectedinseriesacrossthesystemwiththemidpointearthed.使用兩盞燈，每盞燈的額定電壓為系統(tǒng)全電壓，但在系統(tǒng)中串聯(lián)連接，中點(diǎn)接地。L26ElectricityDistributionIfthesystemiscorrectlyinsulatedthenbothlampswillglowathalfbrilliance.Thelampsareplacedclosetogethertoenableacomparisontobemade.#如果系統(tǒng)完全絕緣，那么兩盞燈會(huì)(因?yàn)楦鞯靡话腚妷憾?處于一半亮度。兩盞燈要放在一起，以便能夠做出對比。L26ElectricityDistributionAdirectearthinonepolewillshortcircuititslamp,causingtheothertoshinelightly.Aslightinsulationbreakdownwouldproduceadifferenceinbulbbrightnessbetweenthetwo.#任何一個(gè)直接接地點(diǎn)都會(huì)將其中的一個(gè)燈短路，從而會(huì)使另外的一個(gè)燈變得更亮。輕微的絕緣故障會(huì)使兩個(gè)燈泡的亮度產(chǎn)生不同。L26ElectricityDistributionWhereanearthfaultisdetectedthecircuitbreakersforeachseparatecircuitmustbeopenedinturnuntilthefaultlocationisdiscovered.#在檢測到接地故障的地方，每個(gè)獨(dú)立電路的斷路器必須依次斷開，直到發(fā)現(xiàn)故障位置。L26ElectricityDistributionTheparticularsectionordistributionboxwouldthenhavetohaveitscircuitsinvestigatedonebyonetolocatethefaultandenableitscorrection.#特定的區(qū)域配電箱或者分配電箱則必須要一個(gè)接一個(gè)的調(diào)查它們的電路，然后確定故障并使它們恢復(fù)正常。part3

Exercise&ExaminationAmolded-casecircuitbreakerprovidesprotectionagainstshortcircuitsbyusinga/an_____.A.electromagnetB.shadingcoilC.arcquencherD.burnawaystrip