基于自适应陷波器的构网型直驱永磁风机 SSO 抑制策略研究

Sub-synchronous oscillation (SSO) occurring in power grid can adversely affect the control performance of grid-side converter for grid-forming direct-drive permanent magnet synchronous generators (D-PMSG), thus threatening the stability of entire system. An SSO suppression strategy based on an adaptive notch filter (ANF) was proposed to address this issue. The impact mechanism of SSO on the grid-side control of D-PMSG based on virtual synchronous generators was analyzed thoroughly. Meanwhile, the propagation path of disturbances within the system was clarified. Also, the influence of SSO characteristic variation on the notch filter’s suppression function was studied. Subsequently, an SSO parameter identification algorithm based on an improved fast Fourier transform was developed to address the limitations of fixed-parameter notch filters when dealing with the time-varying characteristics of SSO frequencies, enabling real-time tracking of SSO frequencies. On this basis, a strategy for dynamically updating the ANF center frequency according to parameter identification results was designed, and the optimal intervention position of ANF in the control system was determined to optimize suppression effects. Finally, the suppression effect of the proposed control strategy on SSO was analyzed and verified through the construction of simulation models and experimental platforms.