The Suppression Method of Wind Power Sub-Synchronous Oscillation Using Static Synchronous Series Compensator

In view of the problem of sub-synchronous control interaction (SSCI) when the doubly-fed wind farms transmit power through the series-compensated system, this paper proposes an equivalent positive resistance control method based on SSSC to suppress SSCI. The method uses the current in the grid side as an input signal and produces sub-synchronous voltage reference signal corresponding to sub-synchronous current in the line through the SSSC supplementary active resistance control (SARC) strategy. The SSSC traces sub-synchronous current to make it equivalent to a positive resistance at the sub-synchronous frequency. The grid side resistance is increased by connecting the SSSC in the line, and the system equivalent resistance is increased to a positive value region, thereby mitigating SSCI. In addition, the structure and parameter design method of SARC are introduced in detail. Finally, based on an actual wind farm structure in North China, the simulation model was built in PSCAD/EMTDC. The results show that the system equivalent resistance is in the positive region because SSSC is equivalent to a positive resistance under various operating conditions, thereby avoiding SSCI in the system. The method has advantages of simple parameters setting and easy realization. © 2020, Electrical Technology Press Co. Ltd. All right reserved.