染污绝缘子安全区泄漏电流检测中去除信号干扰方法

,,,(,400044):,4,33,,1.0,,;3,4,:;;;;:TM855:2007210211;:2007212218(90210026);(200707C1C0070244)0,[1],[224],,,,,[526],,,,,,[728],(50mA)(150mA)(150mA)3[223],,,,,,,,,,,,4,VisuShrink(A,B),33,33,4,,11.1,,,,Wiener,,,583252008310Vol.32No.5Mar.10,2008,[9210]1.2Donoho1994VisuShrink,[11212],,,[13215],4,,4,22.1,:4.0m3.7m4.0m;1TDJY21000/10YDJ2900/1506A,30A,IEC60507GB/T45842004[16217]110kV,SGB2200A,11000,1Fig.1ConnectingdiagramofthemeasuringsystemXP2703,35kV,20.2kV11XP270Table1Contaminationmatchedsortsofsamples/(mgcm-2)/(mgcm-2)1()0.030.102()0.101.03()0.202.02.2,,,,,35,33,()[223]30%,,;80%,,(50mA)343.14210min,14.97mA24Fig.2Actualwaveformsofundenoisedandfourdenoisedleakagecurrents4,2(b)(e)24,,2(b)(c),,,,682008,32(5),,;2(d)(e),,0.8,4,34,4,,,,,30.84Fig.3Waveformsofundenoisedandfourdenoisedleakagecurrents(SNR=0.8),:0.8,4,,,,VisuShrink,,,;,30.8,4,,,0.8,,,;;VisuShrink,,,VisuShrink,0.8,4,40.54Fig.4Waveformsofundenoisedandfourdenoisedleakagecurrents(SNR=0.5)3.233(),4,0.25.00.2,4IeB,565:Ie,Ie=14.9749mA;Ie1,Ie2,Ie3Ie4VisuShrink5,4,Ie478,Ie;3,,Ie4Ie,,5,1,,4,1,6:B3,B=0.0928;B1,B2,B3B4435Fig.5EffectivevaluesofundenoisedanddenoisedleakagecurrentswithdifferentSNR63Fig.6Amplitudevalueratiosbetweentriple2harmonicandfirst2harmonicofundenoisedanddenoisedleakagecurrentswithdifferentSNR6,43,,;1,430.5,4;1,,43,,,:,1,,3,;1,4,;3,1,4,0.5,;1,4,;3,1,4;1,443,:1,,2;1,4,;1,50mA,()[1],..:,1990.[2],,..:,2002.[3].90.2.,1997,23(2):31236.ZHENGZhuangchuan.Thediscussionoftheinfluenceofaerosphereconditionsandmeteorologicalphenomenafactors882008,32(5)aboutlargeacreageflashoverinBeijingin90.2.NorthChinaElectricPower,1997,23(2):31236.[4],..,2006(2):7211.HEBo,LINHui.Presentstatusandfutureprospectsforflashoverresearchofcontaminatedinsulators.InsulatorsandSurgeArresters,2006(2):7211.[5],,,..,2005,25(24):1442148.CHENPan,SUNCaixin,MIYan,etal.Researchofbroadbandwidthmicro2currentsensorcharacterforinsulatorleakagecurrentmonitoringsystem.ProceedingsoftheCSEE,2005,25(24):1442148.[6],,..,2006,30(14):71276.PENGXiangang,NIEYixiong,LIUYi.Applicationoffuzzypatternrecognitionininsulationdetectionofinsulatorstring.AutomationofElectricPowerSystems,2006,30(14):71276.[7]..:,2006.[8]..2.:,2003.[9],,..,2005,29(1):65269.ZHOUJing,CHENYunping,ZHOURong.Theapplicationofde2noisebasedoncompromisealgorithmbetweensoft2thresholdingandhard2thresholdingofwaveletcoefficientforfaultlocation.AutomationofElectricPowerSystems,2005,29(1):65269.[10],,,..,2002,26(19):56261.OUYANGSen,SONGZhengxiang,CHENDegui,etal.Applicationofwaveletsoft2thresholdde2noisetechniquetopowerqualitydetection.AutomationofElectricPowerSystems,2002,26(19):56261.[11]DONOHODL,JOHNSTONEIM.Idealspatialadaptationviawaveletshrinkage.Biometrika,1994,81(3):4252455.[12]DONOHODL.Denoisingbysoft2thresholding.IEEETransonInformationTheory,1995,41(3):6132627.[13],,,.CCD.,2005,29(8):83287.ZHAOZhenbing,GAOQiang,LIRan,etal.Near2infraredthermalimagingon2linemonitoringbasedonamonochromeCCDsensor.AutomationofElectricPowerSystems,2005,29(8):83287.[14],,,.Hilbert.,2004,28(5):34239.WANGZhiqun,ZHUShouzhen,ZHOUShuangxi,etal.ParameterestimationofvoltageflickerthroughHilberttransform.AutomationofElectricPowerSystems,2004,28(5):34239.[15]FIGUEIREDOMAT,NOWAKRD.Wavelet2basedimageestimation:anempiricalbayesapproachusingJeffreysnoninformativeprior.IEEETransonImageProcessing,2001,10(9):132221331.[16]IEC507Artificialpollutiontestsonhighvoltageinsulatorstobeusedona.c.systems.1991.[17]GB/T45852004.:,2004.(1977),,,,,:E2mail:[e-mail](1965),,,,:(1975),,,,:ApplicationofDe2noiseMethodsUsedinMonitoringLeakageCurrentinSafetyStageofContaminationInsulatorsLIJingyan,SIMAWenxia,YAOChenguo,SUNCaixin(StateKeyLaboratoryofPowerTransmissionEquipmentandSystemSafetyandNewTechnology,CollegeofElectricalEngineering,ChongqingUniversity,Chongqing400044,China)Abstract:Astheleakagecurrentinthesafetystageofcontaminationinsulatorscomprisesalargequantityofnoises,itisdifficulttoobtainthevalidcharacteristicsofsignals.Fourwaveletthresholdde2noisemethodsareusedrespectivelytofilterthenoisesfrommeasuredleakagecurrentwithdifferentsignal2to2noiseratios(SNR).Threecharacteristics,namely,thewaveforms,effectivevalueandamplitudevalueratioofthetriple2harmonictofirst2harmonicofpre2and2postde2noisedleakagecurrentareacquired,whosede2noiseeffectsarecomparedandanalyzed.Theoptimalwaveletthresholdde2noisemethodfortheleakagecurrentinthesafetystageisselected.ItisshownbyanalysisthatwhenSNRisgreaterthan1.0,thebestde2noisemethodistheself2adaptivethresholdmethodforthewaveformsandtheeffectivevalueofleakagecurrentinthesafetystage.However,theapproximationeffectisbasallythesameforanothercharacteristic,i.e.amplitudevalueratiooftriple2harmonictofirst2harmonic.Asageneralresult,itisknownthattheself2adaptivethresholdmethodisthebestforextractingthecharacteristicsoftheleakagecurrentinthesafetystage.ThisworkisjointlysupportedbyNationalNaturalScienceFoundationofChina(No.90210026)andChongqingUniversityPostgraduatesScienceandInnovationFund(No.200707C1C0070244).Keywords:conta