简介：Techniquesofartificially-triggeredlightninghaveprovidedasignificantlyusefulmeanstodirectlymeasurevariousphysicalparametersoflightningdischargeandtoconductresearchonprotectionmethodsoflightningelectromagneticpulses.Inthisstudy,usingcapacitiveandresistivedividers,currentprobesandopticalfibertransmissiondevices,wemeasuredandanalyzedtheinducedovervoltageontheoverheadtransmissionlineandtheovercurrentthroughSurgeProtectiveDevices(SPD)whenalightningdischargewasartificiallytriggerednearbyonAugust12,2008atConghuaFieldLightningExperimentSite.Thetriggeredlightningdischargecontainedaninitialcurrentstageandeightreturnstrokeswhosepeakcurrentsrangedfrom6.6kAto26.4kA.WefoundthatovercurrentsthroughSPDwereinducedonthepowerlinebothduringtheinitialcontinuouscurrentstageandthereturnstrokeprocesses.Duringthereturnstrokes,theresidualvoltageandthecurrentthroughtheSPDlasteduptothems(millisecond)range,andtheovercurrentsexhibitedameanwaveformupto22/69μswithapeakvalueoflessthan2kA.Basedontheobserveddata,simplecalculationsshowthatthecorrespondingsingledischargeenergywasmuchgreaterthanthevaluesofthehighvoltagepulsegeneratorscommonlyusedintheexperimentsregulatedforSPD.TheSPDdischargecurrentpeakwasnotsynchronoustothatoftheresidualvoltagewiththeformerobviouslylaggingbehindthelatter.TheSPDdischargecurrentpeakwaswellcorrelatedwiththetriggeredlightningcurrentpeakandthewave-frontcurrentgradient.ThelongdurationoftheSPDcurrentisoneofthemajorreasonswhytheSPDwasdamagedevenwithabignominaldischargecurrent.