CharacteristicanalysisofrotordynamicsandexperimentsofactivemagneticbearingforHTR-10GTOriginalResearchArticle

A10MWhigh-temperaturegas-cooledreactor(HTR-10)wasconstructedbytheInstituteofNuclearandNewEnergyTechnology(INET)atTsinghuaUniversityofChina.Theheliumturbineandgeneratorsystemof10MWhigh-temperaturegas-cooledreactor(HTR-10GT)isthesecondphasefortheHTR-10project.Itistosetupadirectheliumcycletoreplacethecurrentsteamcycle.Theactivemagneticbearing(AMB)insteadofordinarymechanicalbearingwaschosentosupporttherotorintheHTR-10GT.Thisrotorisverticallymountedtoholdtheturbinemachine,compressorsandthepowergeneratortogether.Therotorʹslengthis7m,itsweightisabout1500kgandtherotatingspeedis15,000rpm.Thestructureoftherotorissocomplicatedthatdynamicanalysisoftherotorbecomesdifficult.Oneofthechallengingproblemsistoexceednaturalfrequencieswithenoughstabilityandsafetyduringreactorstartup,powerchangeandshutdown.Thedynamicanalysisoftherotoristhebaseforthedesignofcontrolsystem.Itisimportantfortherotortoexceedcriticalspeeds.Somekindsofsoftwaresandmethods,suchasMSC.Marc,Ansys,andthetransfermatrixmethod(TMM),arecomparedtofullyanalyzerotordynamicscharacteristicinthispaper.ThemodalanalysishasbeendonefortheHTR-10GTrotor.MSC.Marcwasfinallyselectedtoanalyzethevibrationmodeandthenaturalfrequencyoftherotor.TheeffectsofAMBstiffnessonthecriticalspeedsoftherotorwerestudied.ThedesigncharacteristicsoftheAMBcontrolsystemfortheHTR-10GTwerestudiedandtherelatedexperimenttoexceednaturalfrequencieswasintroduced.Theexperimentalresultsdemonstratethesystemfunctionsandvalidatethecontrolscheme,whichwillbeusedintheHTR-10GTproject.