第47卷第4期电网技术Vol.47No.42023年4月PowerSystemTechnologyApr.2023文章编号：1000-3673（2023）04-1641-12中图分类号：TM614文献标志码：A学科代码：470·40基于频率耦合阻抗的直驱风电机组次同步振荡关键影响因素分析及抑制措施肖仕武1，徐立光1,2（1．华北电力大学电气与电子工程学院，北京市昌平区102206；2．国网天津市电力公司城西供电分公司，天津市南开区300110）AnalysisofKeyFactorsandSuppressionMeasuresforSub-synchronousOscillationofDirect-drivePMSGBasedonFrequencyCoupledImpedanceXIAOShiwu1,XULiguang1,2(1.SchoolofElectricalandElectronicsEngineering,NorthChinaElectricalPowerUniversity,ChangpingDistrict,Beijing102206,China;2.ChengxiPowerSupplyBranchofStateGridTianjinElectricPowerCompany,NankaiDistrict,Tianjin300110,China)ABSTRACT:Sub-synchronousoscillations(SSO)alwaysoccurwhenthedirect-drivepermanentmagnetsynchronousgenerator(PMSG)isconnectedtotheweakgrid.Theimpedancemodelingmethodconsideringthefrequencycouplingeffectisaneffectiveapproachtostudythisphenomenon.Firstly,consideringthedynamicsofthephase-lockedloop,theDCcapacitorvoltageandtheLC-filter,thefrequency-coupledimpedancemodelofthePSMGisestablished,anditscorrectnessisverifiedbyfrequencyscanning.Secondly,combinedwithamodifiedsequenceimpedanceBodediagramcriterion,thestabilityofthegrid-connectedsystemisdiscriminated,andthenegativeresistanceofimpedanceintheriskyfrequencybandisfoundtobethemaincauseofthesysteminstability.Further,giventhatthevoltageloopandthephase-lockedloopmainlyaffecttheimpedanceinsub/super-synchronousband,theinfluenceofthebandwidthandthedampingratioofthevoltageloopandthephase-lockedloopontheimpedanceisquantifiedbyusingthesensitivityanalysis.Itisfoundthatthedampingratioofthevoltageloopattheinitialparametersisthekeyreasonforthenegativeresistanceoftheimpedance.Finally,animprovedcontrolschemeforaseriesoverrunphasecorrectionlinkisdesigned.Thecontrolschemecanweakenthenegativeresistanceofimpedanceintheriskyfrequencybandbyimpedancereshaping,improvingthestabilityofgrid-connectedsystem.Timedomainsimulationverifiesthecorrec...
