抗雷击架空配电线路的可靠性 毕业论文外文翻译

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1、外文资料翻译ReliabilityofLightningResistantOverheadDistributionLinesLightingcontinuestobethemajorcauseofoutagesonoverheadpowerdistributionlines.Throughlaboratorytestingandfieldobservationsandmeasurements,thepropertiesofalightningstrokeanditseffectsonelectricaldistributionsystemc

2、omponentsarewell-understoodphenomena.Thispaperpresentsacompilationof32yearsofhistoricalrecordsforoutagecauses,duration,andlocationsforeightdistributionfeedersattheOakRidgeNationalLaboratory(ORNL).Distributiontypelightningarrestersareplacedatdead-endandanglestructuresatpole

3、mountedwormerlocationsandathighpointsontheoverheadline.Stationclasslightningarrestersareusedtoprotectundergroundcableruns,padmountedswitchgearandunitsubstationtransformers.Resistancetoearthofeachpolegroundistypically15ohmsorless.Athigherelevationsinthesystem,resistancetoea

4、rthissubstantiallygreaterthan15ohms,especiallyduringthedrysummermonths.Atthesehighpoints,groundrodswererivenandbondedtothepolegroundingsystemsinthe1960'sinanattempttodecreaselightningoutages.Theseattemptswereonlypartiallysuccessfulinloweringtheoutagerate.Fromasurgeprotecti

5、onstandpointthevarietyofpolestructuresused(in-line,corner,angle,deadend,etc.)andthevarietyofinsulatorsandhardwareuseddoesnotalloweach13.8kVoverheadlinetobecategorizedwithauniformimpulseflashoverrating(170kV,etc.)oranumericalBILvoltageclass(95kVBIL;etc.).Forsimplicitypurpos

6、esintheanalysis,eachoverheadlinewascategorizedwithanominalvoltageconstructionclass(15kV,34kV,or69KV).Sixoftheeightoverheadlines(feeders1through6)werebuiltwithtypicalREAStandardhorizontalwoodcrossarmconstructionutilizingsingleANSIClass55-5porcelainpininsulators(nominal15kVi

7、nsulation).Theshieldangleoftheoverheadgroundwiretothephaseconductorsistypically45degrees.Oneoverheadline(feeder7)wasbuiltwithtransmissiontypewoodpoleconstructionbecausethelineextendedtoaresearchfacilitywhichwastohavegeneratedelectricalpowertofeedbackintothegrid.Polestructu

8、reofthislineareofdurablewoodcrossaconstructionwhichutilizedoubleANSI52-3porcelainsuspensi