基于小波分析的SS8主變流器故障診斷研究.pdf

1、中南大學(xué)碩士學(xué)位論文基于小波分析的SS8主變流器故障診斷研究姓名：徐曉東申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：控制理論與控制工程指導(dǎo)教師：蔣新華20060518AbstractInthisdissertationsignificancesoffaultdiagnosisareclarifiedinthebeginningThenthestateofstudyingupaboutfaultdiagnosistheoriestillnowissummar

2、ized，especiallythetheorybasedonwaveletanalysisisdeeplyresearchedandwidelyappliedTheelectriccircuitstructureandworkingprincipleontheSS8ElectricLocomotivesMainConverterareintroducedBasedonanalyzedoftheConverter’sworkingmec

3、hanismthesimulationmodelisbuiltthroughthestronglyMATLAB’stoolSimulinkInfact，therealitycircuitincludeswhitenoisesandkindsofharmonicsItadds3、5harmonicsandwhiteGaUSSnoiseinthesimulationmodelAftermanysimulationexperimentsana

4、lysiswithdifferentconverterfaultstates，differentwaveformsofoutputvoltageareobtainedThepartofsignals’oddsandbreakpointsusuallyhasrichlyandimportantinformationitisoneoftheimportantfeaturesWhenthecircuitwasfault，theoutputsi

5、gnalusuallywouldhavebrokenSodetectingthesignalsingularityisveryimportantinthefaultdiagnosisUsingwavelettransformcaneffectivelydetectthelocationofoddsandbreakpointsInthispaperitappliesmanywaveletbasesandscalestotransformt

6、hefaultoutputThroughcomparingandanglicizingtheresult，thebestscaleandwaveletbasearechosen，leadingtobeneficialexplorationofon—linediagnosisInrealitythesignalhasmanynoises，whitenoiseandcolornoiseSoitisimportanthowtoseparate

7、thesignalfromnoisesandextractthefeaturesInthispaperthemethodofde—noisingisbasedonWave—shrinkagewithwaveletbaseandwaveletpackagebaseComparingthede—noisingresultsusingkindsofshrinkage，itobtainsthefittingde—noisingmethodFea

8、turesextractionmethodisanotherkeyfaCetinthefieldsoffaultdiagnosisItpresentsthefeaturesextractionmethodbasedonwaveletpackageAfterde—noised，thesignalistransformedbywaveletpackagesothatcharactervectorsareconstructedbyobtain