基于小波變換的直流系統(tǒng)接地故障檢測方法研究

1、天津大學碩士學位論文基于小波變換的直流系統(tǒng)接地故障檢測方法研究姓名：任曉棟申請學位級別：碩士專業(yè)：控制理論與控制工程指導教師：李冬輝20040101ABSTRACTGenerallyspeakingitisimportantforsafeoperationofpowersystemthatDCsystemgroundingfaultinpowerplantsandWallSforlTlersubstationsiSdetectedtim

2、elyandexactlyThedetectionmethodoflOWfrequencysignalinjectionwhichiswidelyusediSeasilyinfluencedbythecapacitorsbetweengroundandeachbranchandbytheringnetTosolvetheproblemthisPaDerpresentsanewdetectionmethodbasedonwavelettr

3、ansfotlTland10WfrequencyinjectionThedetailedresearcheshavebeencarriedoutandthemaincontentsoftheresearchinclude：1AnalyzingthemainfactorsthatinfluencethedetectionofDCsystemgroundingfault，andthecompositionofbranchcurrent2Pr

4、oposingageneralschemeofDCsystemgroundingfaultdetectiononthebaseofwavelettransformtheoryinordertoeliminatetheinfluenceofthecapacitorsbetweengroundandeachbranch，andtheringnet3Designinganovelalgorithmbasedonthefilteringprep

5、rocessingofB。splinewaveletaccordingtothecharacteristicofbranchcurrent4ProposingaproportionaldivisormethodandafiducialsignalmethodbasedonthedampedcomplexwavelettransformcoefficientsandprovingthemintheoryPuttingforwardamet

6、hodoflowfrequencycurrentextractiononthebaseofdampedcomplexwavelet5Constructinganinversecomplexwavelet仃趾s矗)malgorithmforspecificsignalProposingthemethodsoflowfrequencycurrentextractionbasedonMorletwavelettransformandwavel

7、etpackettransformrespectively6DesigningaFourieralgorithmbasedsoftwaretocalculatethevalueofeachbranch’Sinsulatingresistanceandvalidatingthedetectionmethodthroughsystemsimulation7SettingupthesimulatingDCpowersupplynetdesig

8、ningandimplementingbasicallythesignalacquisitionandprocessingsystembasedonthecomputercontroltechniqueThissubjectmatterisverymeaningfultoimprovethedetectionofDCsystemgroundingfaultandtoperfectthesafetyandreliabilityofDCsy