MarineEngineeringEnglish《輪機英語》APracticalCourseforEngineersWorkingonBoardShips

MarineElectricalSystemandAutomatizationLesson26Marine

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

ElectricityDistributionSystem.3

4part1

NewWordsandExpressions5part2

TextAnalysisL26ElectricityDistributionThecontrolanddistributionoftheelectricalenergygeneratedbygeneratorsareeffectedbypowerdistributionequipment,i.e.switchboards.#發電機產生的電能的控制和分配受配電設備(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)應急配電盤、(c)區域配電盤(或子配電盤)或(d)分配電盤。8

Introduction(Backgroundknowledge)

L26ElectricityDistributionAmainswitchboardconsistsofthegenerator

controlpanel,theloadpanelandthepaneloftheparalleloperationofthegenerator.#主配電盤由發電機控制屏、負荷屏和發電機并車屏組成。

Introduction(Backgroundknowledge)

Introduction(Backgroundknowledge)

Introduction(Backgroundknowledge)

L26ElectricityDistributionItsmainfunctionisto(1)switchonoroffthecurrentcircuitaccordingtotherequirement(manuallyorautomatically);其主要功能是(1)根據需要(手動或自動)接通或斷開電流回路；L26ElectricityDistribution(2)maketheprotectiondeviceenergizetodisconnecttheelectricalequipmentwiththecircuit,givingthealarmsignalwhenthereissomethingwrongwiththeelectricalpowersupplysystem;使保護裝置通電，以斷開電氣設備與電路的連接，當供電系統出現故障時發出報警信號；L26ElectricityDistribution(3)measureorindicateeveryelectricalparameterssuchasvoltage,current,watt,powerfactoretc.duringtheoperation;測量或指示運行中的電壓、電流、瓦特、功率因數等各項電氣參數；L26ElectricityDistribution(4)adjustthedistributionofthepowerofthegeneratorinparalleloperationorthevoltage,frequencyofthepowerstation;調整并聯運行發電機的功率分配或電站的電壓、頻率；L26ElectricityDistribution(5)indicatethesignaloftheconditionofthecurrentcircuit,theconditionofthebreakersandtheerrorfromthenormalworkingcondition.指示電流回路狀態信號、斷路器狀態和正常工作狀態的偏差。L26ElectricityDistributionThegeneratedsupplyisprovidedtoconductorsknownas“bus-bars”whicharelocatedbehindthemainswitchboard.#產生的電能提供給叫做“匯流排”的導體，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備，或者其它區域配電盤或分配電盤。L26ElectricityDistributionAcircuitbreakerisanisolatingswitch.#斷路器其實就是一個獨立的開關。L26ElectricityDistributionAsectionboardisagroupingofelectricalservicesfedfromthemainboard.#區域配電盤是由主配電盤供電的一組電氣設施。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域板供電。L26ElectricityDistributionAnACdistributionsystemisprovidedfromthemainswitchboardwhichisitselfsuppliedbythealternators.#交流電配電系統的電是由主電板分配的，交流發電機直接向主配電盤供電。L26ElectricityDistributionThevoltageattheswitchboardisusually415butonsomelargeinstallationsitmaybeashighas3,300.#主配電盤上的電壓一般為415伏，但在一些大型的設備上，電壓有可能達到3300伏。L26ElectricityDistributionPowerissuppliedthroughcircuitbreakerstolargerauxiliariesatthehighvoltage.#它通常在高壓狀態下，通過斷路器向大型輔助設置上輸出功率。L26ElectricityDistributionSmallerequipmentmaybesuppliedviafusesorminiaturecircuitbreakers.#而小型的設備則可以用熔斷器(保險絲)或者微型斷路器。L26ElectricityDistributionLowervoltagesuppliesused,forinstance,forlightingat220volts,aresuppliedbystepdowntransformersinthedistributionnetwork.#例如，用于220伏照明的低壓供電，可以在分電網中由降壓變壓器來供電。L26ElectricityDistributionThedistributionsystemwillbethreewireswithinsulatedorearthedneutral.#配電系統是三線(相)絕緣或者中線接地。L26ElectricityDistributionTheinsulatedearthhaslargelybeenfavoredbutearthedneutralsystemshaveoccasionallybeeninstalled.#大多數使用的是三線絕緣的配電系統，中心接地的系統有時也會使用。L26ElectricityDistributionTheinsulatedearthsystemcansufferfromsurgesofhighvoltageasaresultofswitchingorsystemfaultswhichcoulddamagemachinery.#由于斷開與閉合或者可能損壞機器的系統故障，三相絕緣系統可能遭受高壓電涌。L26ElectricityDistributionUseoftheearthedsystemcouldresultinthelossofanessentialservicesuchasthesteeringgearasaresultofanearthfault.#接地系統的使用可能導致一項重要的用途，比如舵機，由于接地故障而喪失。L26ElectricityDistributionAnearthfaultontheinsulatedsystemwouldnothoweverbreakthesupplyandwouldbedetectedintheearthlampdisplay.#然而，絕緣系統中的一個接地故障不會導致供電中斷，同時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)絕緣系統得以青睞。L26ElectricityDistributionInthedistributionsystemtherewillbecircuitbreakersandfuses.#配電系統中會有斷路器和保險絲。L26ElectricityDistributionEquipmentforACsystemsishoweversmallerandlighterbecauseofthehighervoltageandthereforelowercurrents.#然而，交流系統中的電器設備較小和較輕，因為其較高的電壓、較低電流。L26ElectricityDistributionMiniaturecircuitbreakersareusedforcurrentsuptoabout100A

andactasafuseandacircuitbreaker.#微型斷路器用于電流高達100A，起到保險絲和斷路器的作用。L26ElectricityDistributionThedevicewillopenonoverloadandalsointheeventofashortcircuit.#這種設備會在過載和發生短路的情況下自動斷開。L26ElectricityDistributionUnlikeafuse,thecircuitcanbequicklyremadebysimplyclosingtheswitch.#不同于熔斷器(保險絲)，電路還能夠通過開關簡單的閉合來達到電路迅速的恢復。L26ElectricityDistributionAlargeversionofthisdeviceisknownasthemouldedcasecircuitbreakerandcanhandlecurrentsinexcessof1,000A.#這種形式的設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.#優先卸載和接地故障指示也是交流配電系統的一部分。L26ElectricityDistributionPreferentialtrippingisameansofretainingessentialelectricalsupplies.#優先卸載是保持重要電力供應的一種方法。L26ElectricityDistributionIntheeventthatageneratorcannotsupplyalltheloadthennon-essentialloadsaredisconnectedbypreferentialtrips.如果發電機不能向所有的負載供電，那么不重要的負載就被優先卸載所斷開。L26ElectricityDistributionTheintentionistoreducethegeneratorloadwhileensuringessentialequipmentsuchassteeringgear,navigationlights;etc.retainsitselectricalsupply.#這樣的目的就是減少發電機所承受的負載來保證重要的設備，比如舵機、航行燈等等，保持其電力供應。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全電壓，但在系統中串聯連接，中點接地。L26ElectricityDistributionIfthesystemiscorrectlyinsulatedthenbothlampswillglowathalfbrilliance.Thelampsareplacedclosetogethertoenableacomparisontobemade.#如果系統完全絕緣，那么兩盞燈會(因為各得一半電壓而)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.#任何一個直接接地點都會將其中的一個燈短路，從而會使另外的一個燈變得更亮。輕微的絕緣故障會使兩個燈泡的亮度產生不同。L26ElectricityDistributionWhereanearthfaultisdetectedthecircuitbreakersforeachseparatecircuitmustbeopenedinturnuntilthefaultlocationisdiscovered.#在檢測到接地故障的地方，每個獨立電路的斷路器必須依次斷開，直到發現故障位置。L26ElectricityDistributionTheparticularsectionordistributionboxwouldthenhavetohaveitscircuitsinvestigatedonebyonetolocatethefaultandenableitscorrection.#特定的區域配電箱或者分配電箱則必須要一個接一個的調查它們的電路，然后確定故障并使它們恢復正常。part3

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