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,thepropertiesofalightningstrokeanditseffectsonelectricaldistributionsystemcom

2、ponentsarewell-understoodphenomena.Thispaperpresentsacompilationof32yearsofhistoricalrecordsforoutagecauses,duration,andlocationsforeightdistributionfeedersattheOakRidgeNationalLaboratory(ORNL).Distributiontypelightningarrestersareplacedatdead-endandanglestructuresatpolemoun

3、tedwormerlocationsandathighpointsontheoverheadline.Stationclasslightningarrestersareusedtoprotectundergroundcableruns,padmountedswitchgearandunitsubstationtransformers.Resistancetoearthofeachpolegroundistypically15ohmsorless.Athigherelevationsinthesystem,resistancetoearthiss

4、ubstantiallygreaterthan15ohms,especiallyduringthedrysummermonths.Atthesehighpoints,groundrodswererivenandbondedtothepolegroundingsystemsinthe1960'sinanattempttodecreaselightningoutages.Theseattemptswereonlypartiallysuccessfulinloweringtheoutagerate.Fromasurgeprotectionstandp

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

6、lysis,eachoverheadlinewascategorizedwithanominalvoltageconstructionclass(15kV,34kV,or69KV).Sixoftheeightoverheadlines(feeders1through6)werebuiltwithtypicalREAStandardhorizontalwoodcrossarmconstructionutilizingsingleANSIClass55-5porcelainpininsulators(nominal15kVinsulation).T

7、heshieldangleoftheoverheadgroundwiretothephaseconductorsistypically45degrees.Oneoverheadline(feeder7)wasbuiltwithtransmissiontypewoodpoleconstructionbecausethelineextendedtoaresearchfacilitywhichwastohavegeneratedelectricalpowertofeedbackintothegrid.Polestructureofthislinear

8、eofdurablewoodcrossaconstructionwhichutilizedoubleANSI52-3porcelainsuspensi