基于小波变换的电缆在线行波故障测距方法研究

三峡大学硕士学位论文基于小波变换的电缆在线行波故障测距方法研究姓名：陈雪申请学位级别：硕士专业：电力系统及其自动化指导教师：胡汉梅20090401IIMATLAB6.5IIIAbstractWiththedevelopmentofChinapowergridinrecentyears,powercablesarewidelyusedinpowertransmissionandthecablefaultsarealsoarising.Cablelocationisthepreconditionofeliminatingcablefaults.Exactcablelocationcansavetimeinfindingfaultpointandishelpfultoreducefaultloss.Butuptonow,maturecablefaultlocationmethodsintheworldaremostlybasedonoff-lionstatusandthereisstilllackofeffectiveon-linemethod.Soithaspracticalsignificancetostudycableon-linefaultlocation.Basedonwavelettheory,thecableon-linefaultlocation,cablefaultmodelingandfaultsimulationarestudiedandthenewcriterionswhicharehelpfulinimprovingfaultlocationaccuracyaredesignedinthisthesis.Inthispaper,waveletanalysisconceptisfirstintroduced.Beginwithmulti-resolutionanalysisandmodulusmaximums,waveletapplicationinon-linefaultlocationarestudied.Cableparametersandtravelingwavecharacteristicsareintroduced.Polaritycharacteristicsbetweenthreefrontoftravelingwaveinformationandotherfrontoftravelingwavechara-cteristicswhichmayinterferencetheprecisionarestudied.Travelingwaveinformationfromtransientcurrentsandpotentialinfaulttimeisusedinsingle-terminallocationbylinemodeltimedifferencemethod,wavevelocityirrelevantmethodandline-zeromoduletimedifferencemethod.Thosethreemethodsarealsosimulatedandcomparedindifferentfaultsituation.CablefaultmodelisbuildinMatlab6.5andsimulationresultsshowthatwavelettransformcananalysiscablefaulttransienttravelingwaveeffectively,andtheaccuracyoflocationmethodaredifferentindifferentfaultsituation.Thenewcriterionanditsarithmeticaredesignedforimprovingprecision.Keywords:on-linecablefaultlocationsingle-terminallocationwavelettransformI1211.1a.b.c.d.e.12331.21.2.1[1]1.2.21.2.2.141[2]234[3]1.2.2.2[4]5GPS[5]321.2.2.3GISGISGISGISGIS6FODT[6-12]GPS[13]GPSGPSGISGPSGPS1.3123456MATLAB722.12.1.1[15]'(1)spRRyy=++2.1R'/msypy2012345'[1(20)]RkkkkkAραθ°=+−2.2And24ndAπ=20ρ20α20θ1k1.02~1.072k1.02250mm2~1.03250mm23k1.014k1.015k1.01441920.8sssXyX=+2.327810'ssfXkRπ−=×f50Hz'R82.2/msk0.4351py4224441.18()0.312()1920.80.271920.8pccppppXDDyXXssX=++++2.427810'ppfXkRπ−=×f'R2.3pk0.370.8~1cDA4cADπ=scsD=+∆∆py2.42/3sk''200''002()ccsccDDDDkDDDD−+=++2.50D'cD2.1.2x9022FmlnlniiiccqCDDuDDπεπεε===2.6iDcDqiε0εε2.6125.5710FmCGε−=×2.7G1215.5710FmnCGε−=×2.81215.5710FmnCGFε−=×2.91GF2.1.3iLeLeiLLL=+2.1cDµ70410Hmµπ−=×2.2IldxxDc2.110iL2.11cDs02lncIsDµφπ=eL2.127022ln(2ln)10Hm22eccssLIDDµφπ−===×2.10170211()10Hm2icDLD−=−×2.11cD0DsABBxDCIIsdx2.271232(2ln)10HmicsLLLLD−===+×2.122.3ABC2.337123222(ln)10Hm3icLLLsLLD−++==+×2.1311s1=s2=ss3=2s37222(ln)10HmicsLLD−=+×2.142.22.2.1tx[16]2.40R0L0G1uuux∂=+∂1iiix∂=+∂adcbu+G0dxR0dxL0dxixdxi1+--C0dxu12.4KVLabcda00-+d=dduiuuxLxRixxt∂∂+∂∂2.15KCLb00dddddiuuiixCuxxGuxxxtxx∂∂∂∂−+=+++∂∂∂∂2.16dx2.152.16000uiLRixt∂∂++=∂∂2.1712000iuCGuxt∂∂++=∂∂2.18(,)uxt(,)ixt0R0L0G0Cmm(,)2sin()[2][2]ujjtjtuuxtUtIUeeIUeϕωωωϕ=+==2.19mm(,)2sin()[2][2]ijjtjtiixtItIUeeIIeϕωωωϕ=+==2.202.172.18000()dURjLIZIdxω−=+=2.21000()dIGjCUYIdxω−=+=2.2212xxUAeAeγγ−=+2.23121()xxCIAeAeZγγ−=+2.2400ZYjγαβ==+αβ00CZZY=2.232.241xAeγ−2xAeγγ2222222000000001()()2LCRGRLGCαωωω=−++++2.252222222000000001()()2LCRGRLGCβωωω=−+++2.260limtxvtωβ∆→∆==∆2.2713CZ00CLZC=0L0C1050[17]2.2.2[1]iuA2.5tufuiutifiii1Z2Zuiutufz1z2z1A2.52121fuiuZZuZZβ−==+2212tuiuZuZZα==+1uuαβ=+1Z2Zuαuβ1412ua≤≤11uβ−≤≤1221fiiiZZiZZβ−==+1212tiiiZiZZα==+iuββ=−1iiαβ=+12Z=∞uα=2uβ=1iβ=-1iα=00220Z=uα=0uβ=-1iβ=1iα=203fR121ffRZZRZ=+[48]2121112uZZZZKβ−==−++1fKRZ=112iuKββ=−=+212uKKα=+22112iiKKαβ+=−=+4/12tueτβ−=−0ZCτ=C/(12)tiueτββ−=−=−−t=0uβ=-1iβ=1t=τuβ=0.26iβ=-0.26t→∞uβ=1iβ=-15/21tueτβ−=−0LZτ=L/12tiueτββ−=−=−t=0uβ=1iβ=-1t=τuβ=-0.26iβ=0.26t→∞uβ=-1iβ=1153[18]--Multi-solutionAnalysis[19]3.1STFT-[20]2()()tLRψ∈2()LR()ψω()ψω3.1()tψmotherwavelet()2Cdψωωωψ+∞−∞=+∞∫3.116a()tψataψabb()12,,,0abtbtaabRaaψψ−−=∈≠3.2102jxeω−()xψ()xψ3.1.13.13.3,()abtψ[18]()d0ttψ+∞−∞=∫3.32()()ftLR∈2()LR,()abtψ()1*2,,()d,fabtbWTabafttfaψψ+∞−−∞−==∫3.40a≠bt()*tψ()tψ[21]1()ft()gt(),fWTab(),gWTab12()()kftkgt+()()12,,fgkWTabkWTab+2()ft(),fWTab0()ftt−()0,fWTabt−()ft(),fWTab17()()12||,afWTabafbψ=∗3.5()()||1||/2aatatψψ−∗=−()||atψ()ft(),211(),()ddfabftWTabtabCaψψ+∞+∞−∞−∞=∫∫3.63.1.2ab3.1.2.12ja−=2jbk−=,jkZ∈()()22,222jjjjkttkψψ−−−=−3.7a2b3.4()()/2*,2,22()2d,jjjjfjkWTkfttktfψψ+∞−−−∞=−=∫3.81122()(2)jjjkkWfngSfnk−−=−∑3.91122()(2)jjjkkSfnhSfnk−−=−∑3.10kgkh2jWf2jSfjψψ,,(),jkjkftfψψ+∞−∞=∑3.11183.1.2.22ja=jZ∈b/22,()2[2()]jjjbttbψψ−−=−3.122()()ftLR∈/2*(2,)2()[2()]jjjfWTbfttbdtψ+∞−−−∞=−∫3.1300{}nnZaa∈=0(*)()nafnφ=nZ∀∈2()()ftLR∈0j≥/222(*)()jjjnafnφ=nZ∈0j/22(2,)2(*)()jjjjndWfnfnψ==nZ∈21J12{,,,}JJddda⋅⋅⋅⋅0a0aN[22]1/21222()2(*)()(2)jjjjjkkZAtfthAtkφ−−∈==−∑3.141/21222()2(*)()(2)jjjjjkkZDtftgAtkψ−−∈==−∑3.15tn=1122()(*)jjjjjjknnnkkZaAnhaah++−∈===∑3.161122()(*)jjjjjjnnknkkZdDngaag++−∈===∑3.17jh{}nh21j−-jjnnhh=%112221()(2)(2)2jjjjikkkZkZAthAtkgDtk++∈∈=−+−∑∑3.183.2[23]MRA2()()tLRφ∈()()kttkφφ=−19,(),(),kkkkttkkZφφδ′′′=∈3.19()ktφ2()LR0V(){}0kVspantkZφ=∈3.200()ftV∈()()kkkftat