国家电网专业技术人员电力英语水平考试补全短文.docx

国家电网专业技术人员电力英语水平考试补全短文.docx

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国家电网专业技术人员电力英语水平考试补全短文

补全短文

Passage1Functionsofpowertransmission

Thefunctionof

（1）istosendpowerfrompowerplantstoloadcenterortoexchangepowerbetweenpowernetworksinordertoattainthegeneration-consumptionbalanceorthesupply-demandbalancebetween

（2）．Powertransmissioniscompletedbystep-upsubstations，（3）．Thetransmissionlinemainlyconsistsofthetransmissionconductors（cables），polesortowers，insulators，overheadgroundwires，andgroundingdevices.The（4）canreducethelinelossandthevoltagedrop，ensurethepowerquality,raisetheeconomyof（5）．Theincreaseoftransmissionlinevoltagecannotonlyraisetheamountoftransmittedpower,butalsoreducethelinelossandlinevoltagedrop，andimprovethevoltagequality．

A.step-downsubstationsandconnectedtransmissionequipment

B.powernetworkoperation

C.powertransmission

D.transmissionathighvoltage

E.powernetworks

Passage2Substationmisoperationanditspreventing

Themisopemtionthatcanleadto

（1）mainlyare：

①on-loadswitchingofisolatingswitch；②connecting

（2）；③closingthecircuitbreaker（isolatingswitch）withgroundlines（groundswitch）earthed．

The“fivepreventings”for（3）includes：

①preventingthewrongopeningorclosingofcircuitbreaker；②preventingtheonloadopeningandclosingofisolatingswitch；③preventing（4）；④preventingtheclosingofcircuitbreakerwithgroundingwire

connected；⑤preventing（5）．

A.preventingthemisoperationinsubstation

B.theclosingofgroundingswitchwithpoweron

C.accidentsintheelectricaloperationofthesubstation

D.thepersonsfromillegalenteringthelivedbay

E.thegroundingwire（closingthegroundingswitch）withpoweron

Passage3Abriefintroductiononthedevelopmentofsupercriticalboilersandtheirmainadvantages

In

（1）suchasU.S.A，JapanandEuropeancountries，thesupercriticalboilerhasbeendevelopedsincethe60soflastcentury．Ithasbeenprovedbydataandexperience，thesupercriticalunithas

（2）．Asforitsreliability,becausethesteam-waterflowpassagesinsupercriticalboilerissameasthatinthe（3），thereisn’tanythingspecial.Butasfarashydrauliccharacteristic，asymbolofreliability,isconcerned，inasupercriticalboiler,undersupercriticalcondition，mediumisofsinglephasewhichhasa（4）.Sothattheproblemcausedbyunevendistributionofsteamphaseandwaterphasecanbeavoided．Itisadmittedthat,if（5），bothsupercriticalandsubcriticalunitscangetanexcellentreliabilityindex.

A.goodhomogenizationofdistribution

B.someadvancedcountries

C.wholeprocessmanagementisstrengthened

D.greatadvantagesoileconomyandenvironmentalprotection

E.subcriticalonce-throughboiler

Passage4Steamgenerationanduse

Steamisoneofman’sdependableservantsMoreandmoreinthebackground，steamisdoingmoreandmoreworkforman.In

（1）steammaybeseenonlyattheteakettle,buttheelectricityusedmaybegeneratedbyburningcoalorgasandproducingsteamtoturnthegeneratorrotorsinthepowerplantEvenif

（2）bynuclearfission，thegenerationofelectricityisstillaccomplishedby（3）.

IntheU.S.A.thedemandforelectricitydoubleseverytenyears.Forthemostpartwaterresourcessuitableforpowergenerationarealreadyinservice,exceptforemergencystandbyandpeak-loadunits;approximately90%of（4）utilizessteam.The（5）isexpandinginmostcountriesoftheworldexceptforthecountrieswhereavailablewaterpowerresourcesaregreaterthanpowerneeds.

A.firstgeneratingsteam

B.anelectricallyheatedhome

C.useofsteamforelectricpowergeneration

D.thenewgeneratingcapacitybeinginstalled

E.thefuelisuraniumandtheheatissupplied

Passage5Circuitbreaker

Circuitbreakersareautomaticallyoperatedhighvoltage（orhighcurrent）switches.Circuitbreakersarerequired

（1）byswitchingcircuitson，bycarryingloadandbyswitchingcircuitsoffundermanualorautomaticsupervision.Theirdutyisasfollows：

Inclosedpositionthecircuitbreakermustbeagoodconductorforthenormalloadcurrent.Inopenpositionthegapacrossthecontactsshallhavefoilinsulationlevel.Atopeningoperatingthecircuitbreakermustbeable

（2）tomanythousandsofamperes，andindependentlyofthecharacteristicsfrompurelyinductivetofullycapacitive.Atclosingoperationthecircuitbreakermustclosefastandbesafealsoagainstfullshortcircuitconditions.Theymust，therefore，beeffectiveinstantaneouslywhenarecalledupon（3）withoutmovement.Asthecircuitbreakeristhelastlinkinthechainofprotectiveequipment,thecircuitbreakerreliabilityis（4）ofthetotalelectricpowersystemsotheimportance（5）cannotbeoveremphasized.

A·toperformanyswitchingoperationafterlongperiods

B.tocontrolelectricalpowernetworks

C.ofthecircuitbreaker

D.toswitchthecurrentwhichcanbefromafewamperes

E.ofthehighestimportanceforhighreliability

Passage6Theratioofdistancetoheightofpumped-storagepowerplant

Forpumped-storagepowerplant,generallytheratioofdistancetoheight（l）,Distance-heightratio

（2）tothedropbetweenupperandlowreservoirthatisL/H.Theheadofsimplepumped-storagepowerplantconsistsoftwoparts，theyarenaturaltopographicelevationdifferenceandelevationdifferenceformedbydam.Ofcourse,theheadderivedfromtopographicelevationdifference（3），soinselectingplantsite，theconditionthatnotonlyaheightdifferenceisavailablebutalsonoveryhighdamofupperreservoirisnecessaryshouldbeconsidered.SmallerL/Hvalueindicatesashorterwatertransportationline，thentheengineeringconstructioncostcanbesaved.Butinmanycircumstances,topographiccondition（4）,sowecan’tsaythesmallestL/Hvalue（5）.Innewlyconstructedthreelargecapacitypumped-storagepowerplantsinourcountry,theL/Hvaluerespectivelyare：

7.12inGuangzhou.4.12inShisanling，2.40inTianhuangping

A.ismosteconomic

B.isusedtoevaluatetopographicconditionofpowerplant

C.isnotdesirable

D.istheratioofhorizontaldistancebetweenupperandlowreservoir

E.isthebest

Passage7Fuelcells

Fuelcellsaredevicesthatwhenafuelsuchashydrogenorhydrogen-richcompoundsandoxygenaresuppliedtomaterialsarrangedliketheanodeandcathodeofaconventionalbattery,combinetoconvertchemicalenergydirectlyintoelectricalenergy.Unlikeconventionalbatteries.wheretheconversionofchemicaltoelectricalenergyrequiresonlytheclosingofacircuitbetweenthecathodeandanodetoproduceandelectricalcurrent，

（1）.Thesecellsrequirethefuelandoxygenthatwillproducethechemicalreactionsthatproduceanelectrical0utout．Fuelcellshavebeenmadethatwillsupplypowerinthemegawattrange，and

（2）．Suchcellsarenotyetwidelyusedonpowersystems，but（3）tosupplyfuelcellpowertoisolatedloadsAsthevoltageoutputofacellisintheorderoflto2.5V,（4）andpoweroutputinrangesthatarenormallyrequired.Invertersareusedto（5）whenandACoutputisdesired.

A.furtherdevelopmentisunderway

B.thereisnostoragecapacityinafuelcell

C.manycellsareoperatedinseriestoobtainvoltages

D.supplyalternatingcurrentfromfuelcells

E.astheyarebeingdevelopedtherehavebeensomeapplications

Passage8SubstationspaceintotheDigitalAge

Substationsconstitutethemainpartofpowertransmissionanddistributioninapowergrid.Thesubstations

（1）,withtheresponsibilityfortheelectricpowertransmissionanddistributioninthegrid.Overmorethanadecadeofdevelopment,

（2）.Intherebuildingandconstructingofpowergridinruralandurbanareas，automationtechnologyisnotonlyusedinlow-voltagesubstationstorealizeunattendedoperation，butalsointhe220kVandaboveextra-voltagesubstations，thusgreatlyenhancingthelevelofmodernizationofpowergridconstruction,strengtheningthepowertransmissionanddistributionandthepossibilityofpowergriddispatchingandreducingthetotalcostofsubstationconstruction,（3）.However,thedevelopmentoftechnologyisnever-ending，andtheincreasingmaturationoftechnologylikeintelligentswitches，photoelectriccurrentandvoltagetransformers，onlineconditionmonitoringofprimaryequipments,（4）,aswellasthedevelopmentandapplicationofhigh-speednetworkinreal-timesystem，isboundtohaveaprofoundimpactupontheexistingsubstationautomationtechnology,and（5）isabouttoemerge.

A.substationautomationtechnologyhasreachedacertainlevel

B.simulationtrainingtechnologyforsubstationoperation

C.composedofalargenumberofprimaryandsecondaryequipments

D.afull-digitalautomationsystem

E.allofwhichhasbecomeanindisputablefact

Passage9OvercomingtheProblemofWaste

ManylargecitiesareanythingbutbeautifulStreetsarelitteredwithtrash.Inthistrash,however,

（1）．

Ifpeoplewanttosolvetheproblemofwaste,

（2）．Theymustworkoutwaysofmakinguseofgoodthingswhicharejustthrownawayaswaste．Whenacargetstooold，itmaynotrim

anymore.Butifthemetalthatthecarwasmadeofisstillgood，（3）.Whenabottleisempty,itgoesoutinthetrash.Butbottleglasscanbegroundintosandandusedtopavestreets.Besides,garbagefromfoodcanbechangedintofertilizer.Butfirstyouhavetopickoutalltheglassandmetal.

Furthermore,garbagecanalsobeagoodsourceformakingbuildingblocks,whicharethencoveredwithconcrete.Now,（4）.Someday,peoplewillwatchfilmsinagreatcinemawhichhasbeenbuiltoutofgarbageFuturebuildings，roads，andcitiesmaybemadefromgarbage.Butsofar,（5）.

A.thereisnotimetobelost

B.buildingbeautifulcities