大型燃油变压器的破坏-保险英文资料

IMIA16-66(96)EFAILUREOFLARGEOILCOOLEDTRANSFORMERSWorkinggroupreporttothe29thconferenceoftheInternationalMachineryInsurers’Association,September1996ExecutiveSummaryIntroductionScopeofstudyInformationobtainedMethodologyNumbersandamountsoflossesLossesbyagesoftransformersLossesbycausesoffailureLossesbytypesofindustryBusinessinterruptionlossesConclusionsAppendixExecutivesummaryMajorlossesduetofailuresoflargeoilcooledtransformersappearedtobeoccurringwithincreasingfrequencyintheyearsleadingupto1995.AnIMIAWorkingGroupwasestablishedtoexamineandreportonthetopicattheIMIAConferencein1996.Arequestwassenttoallnationaldelegationsseekinginformationonlossesinvolvingtransformersratedat100MVAandabovefrom1989onwards.Inall,informationwasobtainedin75casesoffailuresoflargeoilcooledtransformers,andtheseformedthebasisforfurtherstudy.Thelosseswereexaminedbymarshallingtheinformationforsuccessiveyearsintothefollowingcategories:Numbersandamountsoflosses.Agesoftransformers.Causesoffailures.Typesofindustryusingthetransformers.RatioofBusinessInterruptionlossamountstoPhysicalDamagelossamounts.Thestudyrevealedafairlyevenpatternoflossesovertheyearsreviewedanddemonstratedthatfailuresoflargeoilcooledtransformersarepredominantlyassociatedwiththegeneration,transmissionanddistributionofpower,aremorelikelytoarisefrominternalfailurethanexternalfailure,particularlyduringtheearlyyearsinservice,andamajorfailurecouldcostInsurersbetween$1millionand$3millionforPhysicalDamageandforBusinessInterruptioninthesameorderofmagnitude,althoughanexceptionalBusinessInterruptionlossmayescalatetotensofmillionsofUSdollars.topofmaindocumentIntroductionMajorlossesduetofailuresoflargeoilcooledtransformersappearedtobeoccurringwithincreasingfrequencyintheyearsleadingupto1995.AnIMIAWorkingGroupwasestablishedtoexamineandreportonthetopicattheIMIAConferencein1996.TheWorkingGrouphavesoughttoprovideinformationwhichwouldbeofsomepracticalbenefittotheunderwritingoflargeoilcooledtransformers.Thenatureoftheinformationgatheredwasnotconducivetoarigorousstatisticalanalysis,butsometrendsandpointershaveemergedwhichmayassistintheunderwritingoflargeoilcooledtransformers.topofmaindocumentScopeofstudyApreliminaryreviewofinformationimmediatelyavailableindicatedthatthemajorlosseswhichwereasourceofconcernhadoccurredontransformersratedat100MVAandabove.Arequestwassenttoallnationaldelegationsseekinginformationonlossesinvolvingtransformersratedat100MVAandabove,ideallyfrom1989,oriflossdetailswerenolongeravailableasfarbackas1989,asfarbackasrecordswouldallow.topofmaindocumentInformationobtainedApreliminaryreviewwasmadebyextractinginformationfromtheDetailsofInterestingLargeClaimsappearingintheIMIAdocumentsintheyears1990and1995.Theselossesfortheyears1989to1994produced41casesoffailures.FurtherinformationwasprovidedbythemembersoftheWorkingGroupandbyotherdelegationsinresponsetoarequestforinformation.Inall,informationwasobtainedon75casesoffailuresoflargeoilcooledtransformers,andtheseformedthebasisforfurtherstudy.Lossesoccurringintheyears1989and1990weredrawnfromareducedbaseofinformation,resultinginalownumberofcasesconsideredcomparedwithlateryears.Thishastobetakenintoaccountwheninterpretingthefigureswithregardtotheyearbyyearprogressionoftrends.topofmaindocumentMethodologyItwasintendedtoexaminethelossesbymarshallingtheinformationforsuccessiveyearsintothefollowingcategories:Numbersandamountsoflosses.Manufacturers.Agesoftransformers.Causesoffailures.Typesofindustryusingthetransformers.However,someofthemajorcontributorsofinformationwerenotinapositiontoidentifythemanufacturersofthetransformersinvolved.Astheseoutnumberedtheremainingcases,wherethetransformermanufacturerhadbeenidentified,ananalysisbymanufacturerwasnotundertaken.Anestimateofthetotalinsuredpopulationoflargeoilcooledwouldhavebeenmostusefulbutitwasrecognisedthatitwasimpracticabletoobtainthisinformationinviewoftheblanketnatureofmanyofthepoliciesunderwhichcoverwasprovidedforthetransformers.AllamountsoflosseswereconvertedtoUSdollarsforcomputationalpurposes,usingdollarexchangeratesofFrenchFrancs5.216,GermanMarks1.5405,GreatBritainPounds0.6791,ItalianLira1567,JapaneseYen106.78,NetherlandsGuilders1.7148,SpanishPesetas127.33,SwissFrancs1.2635.topofmaindocumentNumbersandamountsoflossesYearNumberTotalMVAAmount(US$)millionsAveragepercase$millionsAveragepercaseMVA(a)(b)198953162612.3602.472542199086220512.7971.60036819911410282826.3591.88328319941311448237.7062.900407TOTALS755922048152.6502.035374NOTE:(a)totalnumberofcasesforwhichlossamountsareknown.(b)totalnumberofcasesforwhichMVAcapacityisknown,inadditiontolossamount.topofmaindocumentLossesbyagesoftransformers(infive-yearagebands)Year0-56-1011-1516-2021-2525+Notknown198910000041990110110419914010414199271161201993502221519943110224TOTALS2135910621topofmaindocumentLossesbycausesoffailuresThequalityoftheinformationavailablewasnotamenabletoclosedefinitionastocausesoffailureandtwobroadcategorieswerethereforeadopted.Thefirstcategoryincludedthosefailureswhichoccurredduringnormaloperation,andmaythereforeberegardedasintern