Wind-farm-level sub-/super-synchronous oscillation suppression strategy based on generalized reactance sensitivity

Abstract

In recent years, several sub-/super-synchronous oscillation accidents caused by the grid integration of the direct-drive permanent magnet synchronous generator (D-PMSG) have occurred, which seriously threatens the safe and stable operation of the power system. The existing research on the mechanism and influencing factors of sub-/super-synchronous Oscillation (SSO) caused by D-PMSG and the unit-level suppression method of SSO have been deeply studied, but there is still a lack of research on the suppression strategy of wind-farm-level SSO. To address the problem, this paper proposes a wind-farm-level SSO suppression strategy based on generalized reactance sensitivity. Firstly, the variation trend of the external reactance of the D-PMSG and the system’s pole with parameter changing is analyzed, which provides support for characterizing the system’s stability only through the external reactance. Inspired by the idea that impedance sensitivity is used to find key parameters, the concept of generalized reactance sensitivity is proposed to find the dominant units that have a great influence on the system’s stability. Based on this, corresponding SSO suppression strategies are proposed respectively with and without dominant units. Finally, the effectiveness of the proposed strategy is verified by simulation.