美标统一标准固体绝缘材料电压击穿的实验方法Word文档格式.docx

美标统一标准固体绝缘材料电压击穿的实验方法Word文档格式.docx

《美标统一标准固体绝缘材料电压击穿的实验方法Word文档格式.docx》由会员分享，可在线阅读，更多相关《美标统一标准固体绝缘材料电压击穿的实验方法Word文档格式.docx（13页珍藏版）》请在冰豆网上搜索。

1.2Unlessotherwisespecified，thetestsshallbemadeat60Hz.However，thistestmethodissuitableforuseatanyfrequencyfrom25to800Hz.Atfrequenciesabove800Hz,dielectricheatingisapotentialproblem.

1.3ThistestmethodisintendedtobeusedinconjunctionwithanyASTMstandardorotherdocumentthatreferstothistestmethod.Referencestothisdocumentneedtospecifytheparticularoptionstobeused（see5.5）.

1.4Itissuitableforuseatvarioustemperatures，andinanysuitablegaseousorliquidsurroundingmedium.

1.5Thistestmethodisnotintendedformeasuringthedielectricstrengthofmaterialsthatarefluidundertheconditionsoftest.

1.6Thistestmethodisnotintendedforuseindeterminingintrinsicdielectricstrength,direct-voltagedielectricstrength,orthermalfailureunderelectricalstress（seeTestMethodD3151）.

1.7Thistestmethodismostcommonlyusedtodeterminethedielectricbreakdownvoltagethroughthethicknessofatestspecimen（puncture）.Itisalsosuitableforusetodeterminedielectricbreakdownvoltagealongtheinterfacebetweenasolidspecimenandagaseousorliquidsurroundingmedium（flashover）.WiththeadditionofinstructionsmodifyingSection12，thistestmethodisalsosuitableforuseforprooftesting.

1.8ThistestmethodissimilartoIECPublication243-1.AllproceduresinthismethodareincludedinIEC243-1.DifferencesbetweenthismethodandIEC243-1arelargelyeditorial.

1.9Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns，ifany，associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.SpecifichazardstatementsaregiveninSection7.Alsosee6.4.1.

ASTMD149美标原则固体绝缘材料电压击穿实验办法（三）

3.1Definitions:

3.1.1dielectricbreakdownvoltage（electricbreakdownvoltage），n—thepotentialdifferenceatwhichdielectricfailureoccursunderprescribedconditionsinanelectricalinsulatingmateriallocatedbetweentwoelectrodes.（SeealsoAppendixX1.）

3.1.1.1Discussion—Thetermdielectricbreakdownvoltageissometimesshortenedto“breakdownvoltage.”

3.1.2dielectricfailure（undertest），n—aneventthatisevidencedbyanincreaseinconductanceinthedielectricundertestlimitingtheelectricfieldthatcanbesustained.

3.1.3dielectricstrength，n—thevoltagegradientatwhichdielectricfailureoftheinsulatingmaterialoccursunderspecificconditionsoftest. 

3.1.4electricstrength，n—seedielectricstrength.

3.1.4.1Discussion—Internationally，“electricstrength”isusedalmostuniversally.

3.1.5flashover，n—adisruptiveelectricaldischargeatthesurfaceofelectricalinsulationorinthesurroundingmedium，whichmayormaynotcausepermanentdamagetotheinsulation.

3.1.6Fordefinitionsofothertermsrelatingtosolidinsulatingmaterials，refertoTerminologyD1711.

ASTMD149美标原则固体绝缘材料电压击穿实验办法（四） 

4.SummaryofTestMethod

4.2Mostcommonly，thetestvoltageisappliedusingsimpletestelectrodesonoppositefacesofspecimens.Theoptionsforthespecimensarethattheybemoldedorcast，orcutfromflatsheetorplate.Otherelectrodeandspecimenconfigurationsarealsosuitableforusetoaccommodatethegeometryofthesamplematerial，ortosimulateaspecificapplicationforwhichthematerialisbeingevaluated.

4.1Alternatingvoltageatacommercialpowerfrequency（60Hz，unlessotherwisespecified）isappliedtoatestspecimen.Thevoltageisincreasedfromzeroorfromalevelwellbelowthebreakdownvoltage，inoneofthreeprescribedmethodsofvoltageapplication，untildielectricfailureofthetestspecimenoccurs.

5.SignificanceandUse

5.1Thedielectricstrengthofanelectricalinsulatingmaterialisapropertyofinterestforanyapplicationwhereanelectricalfieldwillbepresent.Inmanycasesthedielectricstrengthofamaterialwillbethedeterminingfactorinthedesignoftheapparatusinwhichitistobeused.

5.2Testsmadeasspecifiedhereinaresuitableforusetoprovidepartoftheinformationneededfordeterminingsuitabilityofamaterialforagivenapplication；

andalso，fordetectingchangesordeviationsfromnormalcharacteristicsresultingfromprocessingvariables，agingconditions，orothermanufacturingorenvironmentalsituations.Thistestmethodisusefulforprocesscontrol，acceptanceorresearchtesting.

5.3Resultsobtainedbythistestmethodcanseldombeuseddirectlytodeterminethedielectricbehaviorofamaterialinanactualapplication.Inmostcasesitisnecessarythattheseresultsbeevaluatedbycomparisonwithresultsobtainedfromotherfunctionaltestsorfromtestsonothermaterials，orboth，inordertoestimatetheirsignificanceforaparticularmaterial.

5.4ThreemethodsforvoltageapplicationarespecifiedinSection12：

MethodA，Short-TimeTest；

MethodB，Step-by-StepTest；

andMethodC，SlowRate-of-RiseTest.MethodAisthemostcommonly-usedtestforquality-controltests.However,thelonger-timetests，MethodsBandC，whichusuallywillgivelowertestresults，willpotentiallygivemoremeaningfulresultswhendifferentmaterialsarebeingcomparedwitheachother.Ifatestsetwithmotor-drivenvoltagecontrolisavailable，theslowrate-of-risetestissimplerandpreferabletothestep-by-steptest.TheresultsobtainedfromMethodsBandCarecomparabletoeachother.

5.5Documentsspecifyingtheuseofthistestmethodshallalsospecify:

5.5.1Methodofvoltageapplication,

5.5.2Voltagerate-of-rise，ifslowrate-of-risemethodisspecified,

5.5.3Specimenselection，preparation，andconditioning,

5.5.4Surroundingmediumandtemperatureduringtest,

5.5.5Electrodes,

5.5.6Whereverpossible，thefailurecriterionofthecurrentsensingelement，and

5.5.7Anydesireddeviationsfromtherecommendedproceduresasgiven.

5.6Ifanyoftherequirementslistedin5.5aremissingfromthespecifyingdocument，thentherecommendationsfortheseveralvariablesshallbefollowed.

5.7Unlesstheitemslistedin5.5arespecified，testsmadewithsuchinadequatereferencetothistestmethodarenotinconformancewiththistestmethod.Iftheitemslistedin5.5arenotcloselycontrolledduringthetest，itispossiblethattheprecisionsstatedin15.2and15.3willnotbeobtained.

5.8Variationsinthefailurecriteria（currentsettingandresponsetime）ofthecurrentsensingelementsignificantlyaffectthetestresults.

5.9AppendixX1.containsamorecompletediscussionofthesignificanceofdielectricstrengthtests.

ASTMD149美标原则固体绝缘材料电压击穿实验办法（六）

6.Apparatus6.1VoltageSource—Obtainthetestvoltagefromastep-uptransformersuppliedfromavariablesinusoidallow-voltagesource.Thetransformer，itsvoltagesource，andtheassociatedcontrolsshallhavethefollowingcapabilities.6.1.1Theratioofcresttoroot-mean-square（rms）testvoltageshallbeequalto=265%（1.34to1.48），withthetestspecimeninthecircuit，atallvoltagesgreaterthan50%ofthebreakdownvoltage. 

6.1.3Thecontrolsonthevariablelow-voltagesourceshallbecapableofvaryingthesupplyvoltageandtheresultanttestvoltagesmoothly，uniformly，andwithoutovershootsortransients，inaccordancewith12.2.Donotallowthepeakvoltagetoexceed1.48timestheindicatedrmstestvoltageunderanycircumstance.Motor-drivencontrolsarepreferableformakingshort-time（see12.2.1）orslow-rate-of-rise（see12.2.3）tests.

6.1.4Equipthevoltagesourcewithacircuit-breakingdevicethatwilloperatewithinthreecycles.Thedeviceshalldisconnectthevoltage-sourceequipmentfromthepowerserviceandprotectitfromoverloadasaresultofspecimenbreakdowncausinganoverloadofthetestingapparatus.Ifprolongedcurrentfollowsbreakdownitwillresultinunnecessaryburningofthetestspecimens，pittingoftheelectrodes，andcontaminationofanyliquidsurroundingmedium.

6.1.5Itisimportantforthecircuit-breakingdevicetohaveanadjustablecurrent-sensingelementinthestep-uptransformersecondary，toallowforadjustmentconsistentwiththespecimencharacteristicsandarrangedtosensespecimencurrent.Setthesensingelementtorespondtoacurrentthatisindicativeofspecimenbreakdownasdefinedin12.3.

6.1.6Thecurrentsettingislikelytohaveasignificanteffectonthetestresults.Makethesettinghighenoughthattransients，suchaspartialdischarges，willnottripthebreakerbutnotsohighthatexcessiveburningofthespecimen，withresultantelectrodedamage，willoccuronbreakdown.Theoptimumcurrentsettingisnotthesameforallspecimensanddependingupontheintendeduseofthematerialandthepurposeofthetest，itisoftendesirabletomaketestsonagivensampleatmorethanonecurrentsetting.Theelectrodeareaislikelytohaveasignificanteffectuponthechoiceofcurrentsetting.

6.1.7Itispossiblethatthespecimencurrent-sensingelementwillbeintheprimaryofthestep-uptransformer.Calibratethecurrent-sensingdialintermsofspecimencurrent.

6.1.8Exercisecareinsettingtheresponseofthecurrentcontrol.Ifthecontrolissettoohigh，thecircuitwillnotrespondwhenbreakdownoccurs；

ifsettoolow，itispossiblethatitwillrespondtoleakagecurrents，capacitivecurrents，orpartialdischarge（corona）currentsor，whenthesensingelementislocated