电子类英汉词典

影响电力系统运行的因素HazardstoPowerSystemOperation⑴Theoperationofelectricpowersystemsmaybedisturbedastheresultofanumberofcauses.Thetroublesontheelectriccircuitsareusuallyintheformofbrokenconductorsorcircumstancesinwhichconductorsaretemporarily(orpermanent)connectedtoeachotherortoground.Regardlessofthecauseofthedisturbances,suchtroublesseriouslyinterferewiththeflowofpowerandrequirecorrectiveaction.⑵Overheadlinesarevulnerabletotroublescausedbylightning.Whenlightningstrikesalineoranearbyobject,atransientvoltageiscreatedontheline,Hihg-voltagecircuitshavelargespacingbetweenconductorsandfromconductorstogroundedobjects,suchastowers.Directstrokestosuchlinesareusuallydivertedtogroundthroughoverheadgroundwiresandmaycausenointerferencewithoperation.Occasionallystrokesterminatedirectlyonthepowerconductorsandintroduceontothemtransienttransientvoltagesofsuchmagnitudethatarcheracrossinsulatorstringsmayresult.Onceanarcisestablished,powercurrentflowsthroughituntilthecircuitisdeenergized.Lightningvoltagesmaybeofhighmagnitudebutareofveryshortduration;theirtimeismeasuredinmicroseconds.Asaresult,theireffectsaremostnoticeableatthepointwherethestrokeoccurs.Distributionlines,whichoperateatperhaps12kVorless,aremountedonrelativelysmallinsulators,whichmaybeflashedoverbythevoltageinducedinalineeventhoughthelightningstrokedoesnotcontacttheline.Suchresultingarcsinterferewithoperationandusuallyareeliminatedbydeenergizingtheline.Whenthelineisdeenergized.Thearcisextinguishedand,verycommonly,thelinemaybereenergizingimmediately.⑶Overheadlinesaresubjectedtowindandsleet.Althoughdesignedtowithstandordinarystormloading,practicallytheycannotbedesignedfortheextremeconditionofsleetorwindloading.Hence,occasionallinefailuresoccurasaresultofthesecauses.Failurescausedbywindorsleetareusuallyofsuchnaturethatrepairsmustbemadebeforethelinemaybereenergize.⑷Foreignobjectsmaycontactalineandcausedamage,whichnecessitatesremovalofthelinefromservice.Airplanesmayflyintoaline,anautomobilemayknockapole,aconstructionworkermayrunacraneintoaline,oranexcavatormaydigupacable.Birds,squirrels,snakesandotheranimalsoccasionallyshort-circuitlinesandcauseoutages.⑸Generators,transformers,lines,orothercomponentsmaybeswitchedoutofservicefornormalorroutinemaintenance.Whenswitchingoperationsoccur,transientsaresetuponthepowersystemwhichsometimesproduceserousovervoltages.Suchovervoltagesinturnmaycauseflashoverofinsulatorsorpunctureofsolidinsulation.⑹Equipmentsometimesfailswithoutanyparticulardirectcause.Failuremaybeduetoinadequatedesign.previousoverloads,ornaturaldeteriorationofequipment.⑺Humanerrorsmayproducepower-systemoutages.Switchesmaybeopenedunintentionally.Cuttingoffloads;temporarygroundingelectrodesmaybeputonenergizedcircuitsbymistake;equipmenthandledbyhotlinedevicesmaybedropped.Suchoccasions,althoughrare,mustbeconsideredashazardpossibilitiesinpower-systemdesign.影响电力系统运行的因素⑴影响电力系统正常运行的因素很多。电路故障的形式通常是导体断裂。导体暂时（或永久地）相间接地。不管故障的原因是什么，这些故障都严重干扰电流的输送，需要采取补救措施。⑵雷电容易影响架空线路。当雷电击中输电线路或其附近物体时，线路上产生暂态电压。高压电路的相间以及相对接地体．如杆塔）间均有很大的绝缘距离。当接地线遭受雷击时，雷电可经过架空地线流入大地，不会给运行造成什么影响。但是，有时输电线路会遭受雷击，从而在输电线路上产生倡但很高的暂态电压：这种电压会引起线路绝缘子串的电弧放轨一旦绝缘子串上建立电弧，电流会通过它流动而引起线路断电。雷电过电压具有很高的幅值，但持续时间极短，以微秒计算。由此可见，雷电对系统正常运行影响很大。配电线路的运行电压通常为12千伏或更低，它们由相对较少的绝缘子串悬挂，所以即使雷电不足以击倒输电线路。它也会在线路上引起感应电压，从而导致绝缘子串闪络。这种电弧放电会影响系统运行，通常可通过断电来消除故障。跑路一断，电弧熄灭，此时线路可重新合闸架空线易受到大风和冰雹的侵袭。⑶虽然线路设计时需考虑耐受风暴的影响，但是不可能依据最恶劣的气候条件来设计。所以气候条件也会引起输电线路故障，这种故障必须在线路重新供电之前排除。⑷外来物体有可能接触线路造成损害，此时需切断线路。飞机可能会碰到线路，汽车可能会撞倒电线杆，建筑工人的起重机可能会撞到导线，挖掘机也可能会挖出电缆。鸟儿、松鼠、蛇和其它动物偶尔会使线路短路造成停电。⑸在正常或例行检修时，发电机、变压器、输电线路或其它设备需退出运行。当开关操作时，系统中会出现暂态过程，从而引起非常严重的暂态过电压。这种过电压会造成绝缘子串闪络或固体绝缘击穿。⑹有时设备产生故障并没有什么特别的直接原因。故障可能归因于设计不当、过载，或者设备的自然老化。⑺人为过失也会导致电力系统停电事故。开关可能会被无意中拉开而中断负荷；临时接地体可能被错误地与带电回路相连。由带电装置控制的设备可能被接地。这种情况虽然很少，但在电力系统的设计当中必须考虑它们可能带来的危害。NewWordsmagnitude幅值arcover电弧放电，跳火，飞弧，击（打）穿insulator绝缘体，绝缘子arc弧reenergize断路（开）kV千伏induce感应reenergize使又通上电流necessitate使成为必要excavator挖掘机short-circuit使短咱outage停电transformer变压器overvoltage过电压unintentionally无意地grounding接地（电）electrode电极energized通电的transient短暂的，暂态的divert转向，转做terminate终结，使结束PhrasesandExpressions;1.overheadline架空线2.transientvoltage暂态电压3.high-voltagecircuit高压电路4.groundwire地线5.lightningvoltage雷电电压6.flashover跳火，飞弧，击穿A篇：a.c.balanceindicator,交流平衡指示器a.c.bridge,交流电桥a.c.currentcalibrator,交流电流校准器a.c.currentdistortion,交流电流失真a.c.inducedpolarizationinstrument,交流激电仪a.c.potentiometer,交流电位差计a.c.resistancebox,交流电阻箱a.c.standardresistor,交流标准电阻器a.c.voltagedistortion,交流电压校准器a.c.voltagedistortion,交流电压失真Abbecomparator,阿贝比长仪aberration,象差abilityofantiprereducedcomponent,抗先还原物质能力ablativethicknesstransducer[sensor],烧蚀厚度传感器abrasiontestingmachine,磨损试验机absolutecalibration,绝对法校准absolutecoil,独立线圈absoluteerror,绝对误差(absolute)errorofmeasurement,测量的（绝对）误差absolutegravimeter,绝对重力仪absolutegravitysurvey,绝对重力测量absolutehumidity,绝对湿度absolutemethod,绝对法absolutemoistureofthesoil,土壤（绝对）湿度absolutepressure,绝对压力absolute(pressuretransducer,绝对压力表absolutepressuretransducer[sensor],绝对压力传感器absoluteread-out,单独读出absoluteresolution,绝对分辨率absolutesalinity,绝对盐度absolutestability,绝对稳定性absolutestabilityofalinearsystem,线性系统的绝对稳