發(fā)電廠勵磁變壓器局部放電監(jiān)測去噪技術(shù)及應(yīng)用.pdf

1、重慶大學(xué)碩士學(xué)位論文發(fā)電廠勵磁變壓器局部放電監(jiān)測去噪技術(shù)及應(yīng)用姓名：薛勤申請學(xué)位級別：碩士專業(yè)：電氣工程指導(dǎo)教師：李劍胡明20091204重慶大學(xué)工程碩士學(xué)位論文英文摘要ABSTRACTExcitationtransformerisoneofthekeyequipmentsthatensuregeneratorrunnormallyandsteadilywithsupplyingexcitationcurrenttogeneratorO

2、nlinePartialdischarge(PD)monitoringcallensl／reexcitationtransformerrl／nnormallyandsteadilyDuetotheweaknessofPDsignalsandbignessofinterferences，theextractionofPdpulsesfacesmanydifficultiesThedevelopedtechniques，晰msomeachi

3、evement，havenotmetthedemandofengineeringapplicationyetAimingatthepresentproblems，thisthesisstudiesthedenoisingtechnologyofPDmonitoringinexcitationtransformerthemainjobasfollows：FirstlytheoreticandsimulationresearchworkiS

4、carriedoutonresonantnonmagneticCOreRogowskicoilcunentsensorwhichisusuallyusedinPDmonitoringofexcitationtransformeranddesignacurrentsensorthatCandetectPDsinexcitationtransformerDuetotheimpactofnarrowbandperiodicinterferen

5、cestoPDsignals，thispaperusesecondorderIIRlatticenotchfdtertosuppressnarrowbandperiodicinterferencesSecondlybasedontheanalysisofwaveletdecompositioncharacteristicsofPDsignalsandwhitenoise，thewaveletshrinkagedenoisingisana

6、lyzedinordertodecreasethedistortionofPDpulsecausedbynoiseremovalOptimalwaveletselectionforPDfeatureextractionisstudiedAscanbeseenfromthestudiedresults，thePDS／NratioisincreasedandthedistortionofPDpulsecausedbynoiseremoval

7、isdecreased、析mtheleveldependentthresholdingThemethodiseffectivefortheextractionofPDsignalsThirdlythispaperpresentstheemendatingmethodofexcitationtransformerDuetothecombinationofexcitationtransformerandthesystemofgenerato

8、rthispaperdistinguishingthesignalwhetherisPDbrokeninexcitationtransformerafterdiscussingthecharacteristicsofsignatures；Thispaperalsodiscussthepropagationofsignalinwingding，studydistinguishingwhetherPDisbrokeninexcitation

9、transformerafteranalyzingthepolaritycharacteristicsDe—noisingbythecombinationofwaveletdecompositionandtwoordercascadinglatticefilterandusingthemethodofpulsepolarityanalysisextractingsignalsaimingatthehi【ghamplitudeandlon