Integrated-Microgrid-Laboratory-System

IEEETRANSACTIONSONPOWERSYSTEMS,VOL.27,NO.4,NOVEMBER20122175IntegratedMicrogridLaboratorySystemBoZhao,XuesongZhang,andJianChenAbstract—Thepaperpresentsanintegratedmicrogridlabora-torysystemwithaflexibleandreliablemultimicrogridstructure;itcontainsmultipledistributedgenerationsystemsandenergystoragesystemsandintegrateswithadieselgeneratorthatservesasaback-uppowersourceandflywheelenergystorageforfastbalancingtoprovideuninterruptiblepower-supplyservicesincooperationwiththedieselgenerator.Themicrogridsystem,byadoptingthemaster–slavecontrolstrategy,canbetransitedflexiblybetweengrid-connectedandislandedmodesandcanbedisconnectedfromtheutilitywhenafaultoccursorthepowerqualityfallsbelowspecifiedstandards.Thedevelopedbi-direc-tionalinverterwhichisappliedinthesystemplaysanimportantrole.Thesmallmicrogridsofthissystemareintendedtooperateseparatelyorintheformofonelargemicrogridwithacertainswitchstatus.Furthermore,experimentsoncontrol,protection,andothertechnologieshavebeencarriedout.TheresultsshowthattheoperationconditionsmeettherelatedIEEEStandard1547andpowerqualityrequirements.Theintegratedmicrogridlaboratorysystemisabletooperatestablyandreliablyunderdifferentconditions,includingmodetransitionandfaultevents.IndexTerms—Bi-directionalinverter,dieselgenerator,flywheelenergystorage,master–slavecontrol,microgrid.I.INTRODUCTIONTHEincreaseinthepenetrationdepthofdistributedgen-erations(DGs)andthepresenceofmultipleDGsintheelectricalproximitytooneanotherhavebroughtaboutthecon-ceptofthemicrogrid,whichcanprovidemoretechnicalbene-fitsandcontrolflexibilitiestotheutilitygird[1]–[5].Researchonmicrogridtechnologieshasreceivedincreasinglywidespreadattentionrecently.Manymicrogridtechnologiessuchasen-ergymanagement,controlstrategies,protectionmethods,powerquality,laboratorysystems,andfieldtestshavebeenstudiedinparticular[6]–[12].Asthecarrierofmicrogridtechnologies,themicrogridlaboratorysystemisdesignedtoprovideaverifi-cationplatformfortheresearches.Thedevelopmentoflabora-tory-scalemicrogridsystemswiththeDGsandenergystoragesystemshasbecomeoneofthekeytechnologyproblemsthatneedtobesolvedinmicrogridresearch.Manymicrogridsystemshavebeenbuiltinrecentyearsinternationally.InNorthAmerica,theCERTSMicrogridLab-oratoryTestBed[13]isoneofthemostauthoritativemicrogridManuscriptreceivedOctober06,2011;revisedFebruary01,2012;acceptedMarch13,2012.DateofpublicationMay01,2012;dateofcurrentversionOctober17,2012.ThisworkwassupportedbytheHi-TechResearchandDe-velopmentProgramofChina(863)underContract2011AA05A107.Paperno.TPWRS-00940-2011.B.ZhaoandX.S.ZhangarewiththeZhejiangElectricPowerTestandRe-searchInstitute,Hangzhou,Zhejiang,310014,China(e-mail:[e-mail];[e-mail]).J.CheniswiththeSchoolofElectricalEngineeringandAutomation,TianjinUniversity,Tianjin,300072,China(e-mail:[e-mail]).Colorversionsofoneormoreofthefiguresinthispaperareavailableonlineat(ZeroEnergyDistrict)[14]isacommunity-driveninitiativetocreateoneoftheworld’slargestnetzeroenergydistrictsinthedowntownareaandthemaincampusofCol-oradoStateUniversity.The1-MWFREEDMSystem[15]demonstrationlaboratoryofNorthCarolinaStateUniversitynotonlydemonstratestheCenter-developedtechnologies,butitisalsousedtoshowcasethethird-partyrenewableenergytechnologies,suchassolar,wind,fuelcell,batterystorage,flywheelstorage,andplug-invehicles.PerfectPowerattheIllinoisInstituteofTechnology(IIT)issettinganexampleforsmartgridprojectsthroughoutthecountry.Launchedin2006,thesmartmicrogrid-basedsystemisaground-breakingapproachtoelectricitydistributionandmanagement,creatingareliablepowersystem[16],[17].ManyworkshavebeendoneinEuropeaswell.TheAssociationofEuropeanDistributedEnergyResourcesLaboratories(DERlab)[18]aimstoclusterthebestEuropeanDERlaboratoriesfromeachEUmemberstate,includingIWES,KEMA,AIT,NTUA,CRES,andsoon.EachmemberlaboratoryofDERlabisstronginspecificDER-relatedareas,andtogethertheycoverthewholefieldofdistributedgenerationandsmartgrids.TheDERlabassociationoffersanaccesspointtothetestingcapabilities.Testingofthequalificationsofsystemcomponentsandproductscanbeper-formedaccordingtostandardsorcustomerspecifications.TheMicrogridsConsortium[19]comprisesmajorEuropeanman-ufacturers,powerutilities,andpotentialmicrogridoperatorsandresearchteamswithcomplementaryhigh-qualityexpertise.ThemicrogridsystemsincludetheKythnosmicrogrid,theManheimmicrogrid,CESI,theBornholmmicrogrid,theKozufmicrogrid,andsoon.Europeaninstitutesplayanimportantroleinpromotingmicrogridsystems.InAsia,asmall-scalemicrogridpilotplanthasbeendesignedattheKoreaElec-trotechnologyResearchInstitute(KERI)[20].However,partsofthedistributedpowersourcesinthissystemareemulators,includingthewindturbine(WT)simulatorandphotovoltaic(PV)simulator.ManymicrogridprojectshavebeenconstructedinJapan,includingtheAichimicrogridproject[21],Kyotangoproject,Hachinoheproject,CRIEPI[22],andsoon.Themi-crogridtestbedconstructedatHefeiUniversityofTechnology(HFUT)[23]is