Energy-shaping L2-gain controller for PMSG wind turbine to mitigate subsynchronous interaction

Abstract As the serious stability issue of wind power systems, subsynchronous interaction (SSI) problem has resulted in the significant loss of generation. Much effort is put into investigating the risk for SSI in wind farms by manufacturers and research community. To mitigate SSI for permanent magnetic synchronous generator (PMSG), this paper proposes energy-shaping L2-gain controller (ESLGC) for machine side converter (MSC) and grid side converter (GSC). ESLGC not only assures the global asymptotical stability but also enhances system robustness against disturbances. An aggregated series-compensated PMSG-based wind farm and a multi-PMSG wind power system are adopted to evaluate the effectiveness of ESLGC. The results of eigenvalue analysis and time-domain simulation show better robustness and damping performance of the proposed ESLGC as compared to conventional PI controller and filter-based subsynchronous damping controller (SSDC) under various operating conditions.