ApplicationofanintegratedpowerlinesignalanalysismethodologytothedetectionofmajorrotatingmachineabnormalitiesinnuclearpowerplantsOriginalResearchArticle

Anintegratedandimprovedmethodtodetectandidentifytheabnormalityofmotordrivenrotatingmachineryinnuclearpowerplants(NPPs)usingpowerlinesignalanalysisissuggestedinthiswork.Theprimarygoalofthisworkistoimprovethemotorcurrentsignatureanalysis(MCSA)methodthathasbeenusedasanalternativeorsupplementoftheconventionalvibrationmonitoringsystem(VMS).Throughthiswork,theintegratedsystemusingbothmodulatedfluxdensitymodel(MFDM)androtatingfluxmodel(RFM)isproposed.TheMFDMisbasedonthefactthatthemajormechanicalvibrationofrotatingmachinescanbenormalizedtothemotorair-gapeccentricityandthemodulationofair-gapfluxdensity.Therefore,ifthemajordefectsuchasbearingdefectortheshaftdeformationispresent,itisidentifiablethroughthepowerlinesignalresultingfromthemodulatedmagneticdensity.Moreover,thebrokenrotorbarstateorrotoreccentricityduetoelectricalimbalancecanbeanalyzedusingtheRFM.Theotherimportantfeatureofthissystemisanautomatedabnormalitydetectionanddiagnosisalgorithm.ItispossibletodiagnosetheabnormalitywithoutrelyingonexpertsinNPPs.Theverificationisdonethroughvaryingload/torquetestexperimentaswellasviacomputersimulationinthiswork.Theexperimentalresultsshowthattheyareingoodagreementwiththesimulatedresults.