硕士论文-电力变压器局部放电超高频检测方法的研究

华中科技大学硕士学位论文电力变压器局部放电超高频检测方法的研究姓名：盛梦周申请学位级别：硕士专业：系统分析与集成指导教师：李朝晖;黄兴泉20051227I5001500MHz50ΩGIIAbstractPowerTransformerismainequipmentinElectricPowersystem,anditspriceisveryhigh,soMaintenanceisquitenecessaryforTransformer.ThereareScheduledMaintenanceandBreakdownMaintenanceforTransformertraditionally,traditionalmethodsofMaintenancearecompulsiveandblindfoldthesetwonotonlyspendmanpowerandmaterialresources,butalsobringmorepotentialtroublewhilethecomponentsfrequentlytakendown,andsynchronouslyreducedoveralllifeofTransformer.SincetheseverefaultoftraditionalmethodsofMaintenance,anewoneplaysamoreandmoreimportantrolewhichMaintenanceisdeterminedaccordingtothefieldworkconditionsofTransformer,andthat’swhatwewouldcallConditionBasedMaintenance.ConditionBasedMaintenanceisschemedaccordingtotheresultsofvariousinstrumentsandvisitatorialrecordsofpersonnel,onthebasisoftheanalysisoftechniciansandthecurrentstatusofTransformer.ConditionBasedMaintenanceisconcernedwithmonitoringtechnologyanddiagnosistechnologydeeply,thatistosay,wecangetcurrentstatusofTransformerbysortsofmonitoringmethods.MostoffaultsinvolveinsulationforTransformer,andmonitoringforPartialDischargePDcanreflecttheinsulationstatusofTransformerinadvance,findthefaultwithinTransformerontime,andpreventpotentialandparoxysmalevents.Consideringwhathavediscussedabove,inthisdissertation,IdesignedasetofUHF(ultrahighfrequency)monitoringsystemonPartialDischargeofTransformer.Thissystemcanmonitorthereal-timesignalofPDUHF,andthengettheinsulationstatusandtherunningconditionsofTransformer.ComparingwithtraditionalmethodofmonitoringimpulsecurrentofPDdirectly,UHFmethodhasquiteafewadvantages,suchasbetteranti-jamming,muchmoreinformation,andmoresensitive.TheUHFsignalproducedbyimpulsecurrentofPDcanbereceivedbyUHFsensor,thereisUHFsensorplanehelixantennadesignedinthisarticle,Whosebandwidthisbetween500MHzto1500MHz.Twosidesofthisantennaarefeedby50ohmcoaxialline,theHertzianwavessignalisconvertedtohighfrequentcurrentsignalbytheIIIsamefrequencyandthecurrentsignalcanbetransferredintoindustrycomputerbycoaxialline.Thesignalfrequencyreceivedbytheantennaisveryhigh,normallyitcanexceedoneGHz.Usuallythesamplecardcannotcollectsohighfrequencysignal,anditisnotnecessarytocollectthetotalsignalbecausewhatweneedisthepeakvalueofthesignal,andthentoknowtheseveredegreeofthePDofTransformerrelatively.AsignaldisposalcellbasedonFrequencyMixingisdesignedinthisdissertation,itcanreducethefrequencyoforiginalUHFsignaltofacilitateacommonsamplecardanditisnotattheexpenseofPeak-ValueandphasiccharacteroforiginalUHFsignal.KeywordsPowerTransformerConditionBasedMaintenancePartialDischargeUltraHighFrequencyFrequencyMixing____________111.11000pc(8000pc)[1]IEC2(1)(2)(3),[2](1)(2)(3)(4)3300MHz[3]0.33GHzUHF[4-5]UHFUHFSF6GISGIC[6-7]1.231.2.1(1)(2)5001500MHz(3)G(4)VisualC++1.2.2VisualC++422.1[8]2.1.1IEC10kHz2030kHz100kHz200400kHz(1)(2)1MHz(3)2.1.2[9]570150kHz2.1.3500700nm[10]2.1.4DGADissolvedGasAnalysisDGA6IEC[11]2.1.530MHz[12,13]2.1.62.2[14]7IEC270IEC2702.32.3.1UHFUHFGHzKEMARutgersStrathclydeJudd1GHz[15,16]300MHz3000MHz82.3.2200MHz[17]UHF5001500MHz2.3.3GIS[18-20]GISUHFGIS1pC[21]UHF[17]KEMARutgers1GHz3001200MHzUHFUHF20pC[22]StrathclydeJuddGIS[23][24,25]disccoupler9UHF[26-29]ALSTOMK.Raja[30,31][32-35]][36]UHF1011350503-13-15001500MHz[3]503.13.1.1123-2[37](1)rEϑϕϑϕ),(ϕϑfEHEH100%13011001),(ϕϑF(2)LinPPPPP+==ΣΣΣηinPΣPLPinPΣPLP0I0R'ΣR'LR'20'20020212121LLinRIPRIPRIP===ΣΣ'''LRRR+=ΣΣη11≈η(3)1410220Σ=ΣΣ=Σ==rravrravEESSDS),(ϕϑavSΣP0ΣPE),(ϕϑavE),(ϕϑAfE=A),(ϕϑf),(ϕϑ15wwZfAEZEHS2),(2121222ϕϑ===∫=ΣsSdsPϕϑϑddrdssin2=∫∫∫∫==Σππππϕϑϑϕϑϕϑϑ20022222002sin),(2sin2ddrfZAddrZEPww∫∫∫∫•=•===ΣΣππππϕϑϑϕϑπϕϑϑϕϑπππ200222002222220sin),(241sin),(24144ddfZAddrfZArrPrPSwwav),(ϕϑ∫∫==ππϕϑϑϕϑϕϑπ20022sin),(),(4ddffSSDav∫∫∫∫===ππππϕϑϑϕϑπϕϑϑϕϑϕϑπ20022002002maxmaxsin),(4sin),(),(4ddFddffSSDav),(00maxϕϑf),(00ϕϑ16ΣΣ=PPD00ΣP(4)DD10220PinPinavPinPinavEESSG====0inP0ininPPG=ηηη•=•===ΣΣΣΣDPPPPPPGinin000/GDη1≈ηDG≈(5)17(6)nff/2∆nf183.1.2TEM[38](1)(2)5001500MHz(3)(4)(5)200MHz400MHz[38]500MHz1500MHz205019593-3193-3Φ=aerr03-33-3500MHZ-1500MHZ5001500MHZ2.02.0ϕ00arr+=rr0a020AB[39]3-4ABAPBQPQOOPr=PBPAa0rQPπ≈'PPλπππππ/20•+=+rrkπλ2/=rPPπ2πλ2/60o80o3-4ϕ00arr+=0r0a,ϕ()[40]K1.25Kmax21Kmin/4[39](1)DmaxλDπmax25.1λ(2)02rAB4/2min0λrminλ(3)0aD0a10(4)188.5Ω200ΩVC3-5122.21.5mm3-5223.1.350Ω143-6[41]3-6aZCZL2ZCZC/2ZL/4baabZC/4ZCZL/23-6b3-6c3-6a3-6b142v23c3-614233-6aI13-6bI23-6cLCinZZIVIIVZ412)(22121==≈+=3-6dbI2bC3.1.43.2(1)(2)(3)24Ω50SYV507Ω502mm(1)cZcZdDdDZrrcln60lg138•=•=εεrε26.2=rε27.0=rε56.2=rεDd(2)20100mMHzf45=1575−−−SYVmdB/082.0=β1875−−SYVmdB/026.0f∝βUHF3.33.3.125,,,,AMKHzKHz1605535KHz465MM8705.48MHz38,(1)(2)(3)3.3.226tUtUCcmCωcos)(=tUtUmΩ=ΩΩcos)(,ttMUttkUUtUCacmCmcmAMωωcos)cos1(cos)cos()(Ω+=Ω+=Ω3-7(a))(tUΩ)(tUC)(tUAM,cmUtkUmΩΩcos3-73.3.3,3-827uS(t)uI(t)uL(t)3-8Cf)(tUSLf)(tUL,If)(tUICLIfff−=tftkUtUCUcmSπ2cos)](1[)(Ω+=tfUtULLmLπ2cos)(=tftkUtUIUIπ2cos)](1[)(ImΩ+=CfIf3-93-10a28b3-9(a)(b)ffCffLfI=fL-fC(a)(b)3-10[42]10M3.4[42]10M29VCOLNA3-113.4.1LNALC(1)(2)NF3dBMAXIM30GNDGNDRFINVCCGNDRFOUT123456470pF10nH3pF470pF