电力专业英语

1南京工程学院期末考查报告书电气工程专业外语B院（系、部、中心）电力工程学院专业电气工程及其自动化班级电气071学生姓名褚楚学号206070819任课教师朱建忠2010年7月南京成绩2考查要求：1、对已学的课程内容进行总结,节选4篇课题作为报告的主题。2、通过文献的搜索（可借鉴Google、Yahoo和电子图书馆的外文期刊），查找数篇与课程相关的资料（一定是经过选择后的文献，要最好的）。3、通过已经掌握的专业词汇和课题背景对已查找的文献进行精心分析，分析角度可从词汇、语法和课题背景等。4、对文献进行通篇翻译，翻译最好可直译，遇拗口的语句可选择意译。5、翻译后从文中选出关键字。6、总结翻译成果，写下中心思想。7、考查报告总结（语句需简洁）。3Page1.TheProductionofElectricalEnergy(电能生产)1.EnglishtestFromreference1Inlargesteampowerplants,thethermalenergystoredinsteamisconvertedintoworkbymeansofturbines.Aturbineconsistsessentiallyofashaftorrotorfixedinbearingsandenclosedinacylindricalcasing.Therotorismadetoturnsmoothlybymeansofjetsofsteamfromnozzlesaroundtheperipheryoftheturbinecylinder.Thesesteamjetsstrikebladesattachedtotheshaft.Centralpowerstationsemploycondensingturbinesinwhichthesteampassesintoacondenserafterleavingtheturbine.Condensationiseffectedbythecirculationoflargequantitiesofcoldwaterthroughthetubesofthecondenser,thusincreasingtheexpansionratioofthesteamandtheconsequentefficiencyandworkoutputoftheturbine.theturbinesareconnecteddirectlytolargeelectricitygenerators.Inturbinestheactionofthesteamiskinetic.Thereisprogressiveexpansionofthesteamfromthehighpressureandrelativelysmallvolumeatwhichitenterstheturbinetothelowpressureandrelativelyverygreatvolumeatwhichitleaves.Steamismadebyheatingwaterinaboiler.Theusualboilerhasafurnaceinwhichfuelisburnedandtheheatgivenoffduringcombustionisconductedthroughthemetalwallsoftheboilertogeneratesteamatapressurewithintheboilervessel.Innuclearplants,steamisgeneratedwiththeaidofareatorinwhichthecontrolledfissionofuraniumorplutoniumsuppliesthenecessaryheatforthevaporizationofwater.Thusthereatorreplacesthesteamgeneratorofconventionalplants.Keywords：turbine,steamFromreference2Upuntilnowwehavebeenmainlyconcernedwithminimizingthecostofoperatingapowersystem.Anoverridingfactorintheoperationofapowersystemisthedesiretomaintainsystemsecurity.Systemsecurityinvolvespracticesdesignedtokeepthesystemoperatingwhencomponentsfail.Forexample,ageneratinguntilmay4havetobetakenoff-linebecauseofauxiliaryequipmentfailure.Bymaintainingproperamountsofspinningreserve,theremainingunitsonthesystemcanmakeupthedeficitwithouttoolowafrequencydroporneedtoshedanyload.Similarly,atransmissionlinemaybedamagedbyastormandtakenoutbyautomaticrelaying.Ifincommittinganddispatchinggenerationproperregardfortransmissionflowsismaintained,theremainingtransmissionlinescantaketheincreasedloadingandstillremainwithinlimit.Becausethespecifictimesatwhichinitiatingeventsthatcausecomponentstofailareunpredictablethesystemmustbeoperatedatalltimesinsuchawaythatthesystemwillnotbeleftindangerousconditionshouldanycredibleinitiatingeventoccur.Sincepowersystemequipmentisdesignedtobeoperatedwithincertainlimits,mostpiecesofequipmentareprotectedbyautomaticdevicesthatcancauseequipmenttobeswitchedoutofthesystemiftheselimitsareviolated.Ifanyeventoccursonasystemthatleavesitoperatingwithlimitsviolated,theeventmaybefollowedbyaseriesoffurtheractionsthatswitchotherequipmentoutofservice.Thisisusuallyreferredtoasasystemblackout.Keywords：powersystem,securityFromreference3Systemmonitoringprovidestheoperatorsofthepowersystemwithpertinentup-to-dateinformationontheconditionsonthepowersystem.Generallyspeakingitisthemostimportantfunctionofthethree.Fromthetimethatutilitieswentbeyondsystemsofoneunitsupplyingagroupofloads,effectiveoperationofthesystemrequiredthatcriticalquantitiesbemeasuredandthevaluesofthemeasurementsbetransmittedtoacentrallocation.Suchsystemsofmeasurementanddatatransmission,calledtelemetrysystems,haveevolvedtoschemesthatcanmonitorvoltages,currents,powerflows,andthestatusofcircuitbreakersswitchesineverysubstationinapowersystemtransmissionnetwork.Inaddition,othercriticalinformationsuchasfrequency,generatorunitoutputsandtransformertappositionscanalsobetelemetered.Withsomuchinformationtelemeteredsimultaneously,nohumanoperatorcouldhopetocheckallofitinareasonabletimeframe.Forthisreason,digitalcomputersare5usuallyinstalledinoperationscontrolcenterstogatherthetelemetereddata,processthem,andplacetheminadatabasefromwhichoperatorscandisplayinformationonlargedisplaymonitors.Moreimportantly,thecomputercancheckincominginformationagainstprestoredlimitsandalarmtheoperatorsintheeventofanoverloadorout-of-limitvoltage.Stateestimationisoftenusedinsuchsystemstocombinetelemeteredsystemdatawithsystemmodelstoproducethebestestimate(inastatistical)ofthecurrentpowersystemconditionsor“state”.Keywords：telemeter,estimateFromreference4Themainobjectiveofproductioncontrolinpowersystemistominimizethecostofgeneratedpowerwhilemaintainingitsqualityandsatisfyingthesystemsecurityconstraints.Thisimpliesdirectlythatlossesinboththegenerationandthetransmissionofelectricalenergymustbeassmallaspossible.Allparticipatinggeneratorsarerunathighefficiencies,themixofproductionresourcesisexploitedeconomicallyandtheenergyistransmittedoptimally.Productioncontrolincludesgeneralbothactiveandreactivepower.However,themaininterestinthistypeofapplicationhassofarbeenfocusedmainlyontheactivepart.Thisisthecaseinthissectio