There is a problem of multiple sub/super-synchronous oscillation events occurring in a system where the wind power transmission lines are connected to the grid through series compensators. To help tackle this, first, the impedance model of a DFIG based on active and reactive decoupling control is derived. Secondly, the influence of the power grid, DFIG control and motor parameters on the stability of the wind power integrated system is analyzed. Because of the phenomenon of sub/super-synchronous oscillation caused by the parameters of series compensation transmission line and DFIG control parameters, an additional damping controller, added to the rotor side converter control link of the DFIG, is proposed. Also the influence of the damper placed in the power outer loop and the current inner loop on the rotor side converter control link is compared and analyzed. It is concluded that when the damper is placed in the current inner loop, a better effect on the sub/super-synchronous oscillation suppression can be obtained. Finally, the DFIG model is built in PSCAD/EMTDC. The correctness of the impedance model and the effectiveness of the proposed method to suppress the sub/super-synchronous oscillation are verified via time-domain simulations. This work is supported by the Key Project of NSFC and High-Speed Rail Joint Foundation (No. U1434203).