HARMONICDISTORTIONANDREACTIVEPOWERCOMPENSATIONINSINGLEPHASEPOWERSYSTEMSUSINGORTHOGONALTRANSFORMATIONTECHNIQUEW.Hosny(1)andB.Dobrucky(2)(1)UniversityofEastLondon,England(2)UniversityofZilina,SlovakRepublicABSTRACTThispaperreportsanovelstrategyforanalysingasinglephasepowersystemfeedinganon-linearload.Thisstrategyisbasedonanewtheorytotransformthetraditionalsinglephasepowersystemintoanequivalenttwo-axisorthogonalsystem.Thissystemisbasedoncomplementingthesinglephasesystemwithafictitioussecondphasesothatbothofthetwophasesgenerateanorthogonalpowersystem.Thiswouldyieldapowersystemwhichisanalogoustothethreephasepowersystembutwiththephaseshiftbetweensuccessivephasesequaltoл/2insteadof2л/3.ApplicationofthisnovelapproachmakesitpossibletousethecomplexorGaussdomainanalyticalmethodinasimilarwaytothewellknownmethodofinstantaneousreactivepowerforthreephasepowersysteminstigatedbyAkagietalin1983.Thus,forthefictitioustwo-axisphasepowersystem,theconceptofinstantaneousactiveandreactivepowercouldbeinstigated.Moreover,theconceptofinstantaneouspowerfactorcouldbedefined.Thenovelstrategyofpowersystemanalysisoutlinedinthispaperisappliedtoasinglephasepowersystemfeedinganon-linearloadinconjunctionwithanactivepowerfilter.Thelatterservesthepurposeofcompensatingforeitheroftheinstantaneousreactivepowerortheharmoniccurrentdistortioninthesinglephasepowersystemunderinvestigationorforcompensatingofboth.Experimentalresultsdemonstratedtheeffectivenessofthenovelsinglephasepowersystemanalysisreportedinthispaper.Keywords:singlephasepowersystems,orthogonaltransformationtechnique,harmonicdistortionandreactivepowercompensation1INTRODUCTIONInthissectiontheorthogonaltransformationtechniqueappliedtoasinglephasepowersysteminstigatedbyAkagietal,reference[1],isdescribed.Byadoptingthistechniqueexpressionsforthereferencecurrentsusedinanactivepowerfilterforthecompensationofharmonicdistortionorreactivepowerorboth,arederived.Considerasinglephasepowersystemwhichisdefinedbyitsinputvoltageandinputcurrentasfollow