【英文标准名称】:StandardTestMethodforRelativeResistancetoVentedWater-TreeGrowthinSolidDielectricInsulatingMaterials
【原文标准名称】:固体介电绝缘材料对应通气孔水柱上升的电阻力的标准试验方法
【标准号】:ASTMD6097-2001a(2008)e1
【标准状态】:现行
【国别】:美国
【发布日期】:2001
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:D09.12
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:electricalbreakdown;soliddielectrics;treeing;water-treeing;Dielectricapplications;Electricalbreakdown;Extrudedpolymericinsulation;Soliddielectrics;Solidnon-blackthermoplastic/crosslinkedelectricalinsulation;Treeing;Ventedwater-treeg
【摘要】:Thisisalaboratorytestdesignedtosimulatethegrowthofventedwater-treesinthesoliddielectricinsulatingmaterialinitiatedbyasharpprotrusionattheinsulatingandconductiveinterfaceunderawetenvironmentinahighelectricalfield.Water-treeingisthephenomenonwhichdescribestheappearanceoftree-likegrowthinorganicdielectricsunderanacfieldwhenexposedtomoistenvironments.Twotypesofwater-treesareformed.Bowtietrees(withinthedielectric)andventedwater-treesformedfromconductive/insulatingmaterialinterfaceintotheinsulatingmaterial.Thewater-treesreferredtointhistestmethodaretheventedtype.Theinsulatingmaterialisthesoliddielectricorganicmaterial.Theconductivematerialisthesaltsolution.Thissaltsolutionisusedonbothsidesoftheinsulatingmaterialtosimulatethesameinnerandoutersemiconductiveshieldssaturatedwithmoisturebetweentheinsulationlayerusedinamedium-voltageundergroundpowercable.Thistestmethodprovidescomparativedata.Thedegreeofcorrelationwiththeperformanceinservicehasnotbeenestablished.Thestandardtestconditionsaredesignedtogrowasufficientwater-treelengthformostsoliddielectricinsulatingmaterialsofinterestbeforeelectricalbreakdownoccurs.Materialswithaveryhighresistancetowater-treegrowthmayrequirealongertimeundertestconditions(suchas180days)orhighervoltage(suchas10or15kV)inordertodifferentiatetheirperformance.Formaterialswithaverylowresistancetowater-treegrowth,electricalbreakdownmayoccurduringthe30-daytestingtime.Ashortertestingtime(suchasoneortendays)isrecommendedtopreventelectricalbreakdownduringtestingforthoselowwater-treeresistantmaterials.Othervoltages,frequencies,temperatures,aqueoussolutions,anddefectscanbeusedtoevaluatespecificmaterialsforspecificapplications.Temperaturesshouldnotexceedthesofteningormeltingpointofthematerialor10to15x00B0;Cbelowtheboilingpointofthesaltsolution.Anynonstandardconditionsshouldbereportedalongwiththeresults.Tree-growthratesgenerallyincreasewiththetestfrequency.Anaccelerationfactorduetofrequencyisgivenby(f/60)kwherefisthetestfrequencyandkisbetween0.6and0.7.Thetestfrequencyof1kHzisselectedtoacceleratethewater-treegrowth.However,thechemicalnatureofoxidizedproductsfromwater-treeingmaybedifferentatdifferentfrequencyranges.Twoassumptionsforthistestmethodare:(1)alltestedmaterialsgrowtreesinthesamepowerlawkineticmannerand(2)thetimeundertestconditionsof30daysislongenoughtoestablishthedifferenceinwater-treegrowth.Ifthereisadoubt,atleastthreedifferenttestingtimes(suchas30,90,and180days)shouldbeusedtoverifytheircomparativeperformanceanddisclosetheirkineticnatureofwater-treegrowth.Ofcourse,itisalsoassumedthatallwater-treedregionsareoxidizedregionsthatcanbestainedforopticalobservation.Differentmaterialsmayalsohavedifferenttemperaturesandtimestostaintheoxidized(treed)regionsduetotheirdifferentsofteningtemperature.1.1Thistestmethodcoverstherelativeresistancetoventedwater-treegrowthinsolidtranslucentthermoplasticorcross-linkedelectricalinsulatingmaterials.Thistestmethodisespeciallyapplicabletoextrudedpolymericinsulationmaterialsusedinmedium-voltagecables.1.2ThevaluesstatedinSIunitsaretoberegardedasstandard.Nootherunitsofmeasurementareincludedinthisstandard.