Asymmetrical Fault Ride Through as Ancillary Service by Constant Power Loads in Grid-Connected Wind Farm .pdf

《Asymmetrical Fault Ride Through as Ancillary Service by Constant Power Loads in Grid-Connected Wind Farm .pdf》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。

1、1704IEEETRANSACTIONSONPOWERELECTRONICS,VOL.30,NO.3,MARCH2015AsymmetricalFaultRideThroughasAncillaryServicebyConstantPowerLoadsinGrid-ConnectedWindFarmNadeemJelani,Member,IEEE,andMartaMolinas,Member,IEEEAbstractTheintroductionofdistributedgeneration(DG)intoandenhancingtheirfaultridethrou

2、gh(FRT)capabilityislowvoltage(LV)systemsdemandsthatthegenerationsystemre-indispensableinordertoincreasethepowersystemstabilitymaingridconnectedduringvoltagesagstoensuretheoperationalandreliability[4],[5].Additionally,formicrohydroapplica-stability.TheDGconsistingoffixedspeedsquirrelcagei

3、nductiontions,SCIGisstillthecosteffectiveandreliablepowergen-generator(SCIG)-basedwindturbinesisunabletoprovidereac-tivepowercontrolandneedsadedicatedcompensatingdevice.erationsource.Underasymmetricalgridfaultsthenegativesequencefluxcircu-Tomaintainthestabilityoftheutilitygrid,gridoperat

4、orshavelationintheairgapintroducesthetorqueoscillationsthatleadspecifiedtherequirementsfortheintegrationofDERs.Forwindtothereductionoflifetimeofthegenerationsystem.Thispaperpowerplants,thegridconnectionrequirementsdemandFRTproposestheuseofdistributedconstantpowerloads(CPLs)forcapabilitya

5、ndreactivecurrentinjectioninordertomaintaintheasymmetricalfaultridethrough(FRT)insteadofusingacentral-izedSTATCOM.Ithasalsobeenobservedthatthecompensationstabilityofthepowersystem[6]–[10].InUK,FRTcapabilityofnegativesequencevoltageimprovestheperformanceofSCIGrequirementsdemandthattermin

6、alvoltageofthewindfarmbyeliminatingthetorqueripples.Thecompensationofpositiveshouldnotbelessthan15%ofthenominalvoltageduringthesequencevoltageavoidsapossiblevoltagecollapseattheLVdistri-faultanditmustberestoredto90%within0.5s.Gridcodesinbutionlevelandimprovesthereliabilityandstabilityof

7、thewindDenmarksettheminimumvoltagelevelduringthefaultto25%farm.CentralizedcompensationoftheasymmetricalgridfaultbyaSTATCOMiscomparedwiththedistributedcompensationbyofthenominalvoltageanditshouldberestoredto75%withinCPLs.TheresultssuggestthateachindividualCPLinjectslower0.75s[6]