1. North China Branch of State Grid Corporation of China, Beijing 100053, China; 2. School of Electrical Engineering, Northeast Dianli University, Jilin 132012, China

According to the mechanism of subsynchronous resonance(SSR)in doubly-fed induction generator(DFIG)based wind turbine, the electromagnetic torque variation under the variation of rotor speed can be divided into two parts, i. e. , the rotor torque variation and the stator torque variation. Based on the rotor-side converter in the DFIG-based wind turbine, a new additional damping control strategy for suppressing SSR is proposed. An additional controller is added to the rotor-side coverter. Then an additional torque which is in opposite phase with the rotor speed is generated to provide positive damping for the system. Finally, PSCAD/EMTDC is applied to simulate and verify the proposed strategy. The results show that SSR can be effectively suppressed by applying the additional damping control strategy to the rotor side converter.