Sh. Moradinejad Dizgah - Department of Electrical Engineering, Shahid Beheshti University, Tehran, Iran
M. Sedighizadeh - Department of Electrical Engineering, Shahid Beheshti University, Tehran, Iran
A. Goodarzi - Department of Electrical Engineering, Sharif University of Technology, Tehran, Iran
e afjei - Department of Electrical Engineering, Shahid Beheshti University, Tehran, Iran

The wind power penetration is growing in the power systems all over the world due to its numerous privileges. The newly installed wind farms are often far-located and require new transmission lines to get integrated into conventional powersystems. To dispel the financial and technical complications, series compensation is engaged in transmission lines to facilitate the generated wind power into the power system. However, theseries-compensated transmission line is highly exposed to a detrimental phenomenon in power system called subsynchronous resonance (SSR). In this paper, SSR is investigated in a doublyfedinduction generator (DFIG) based wind farm connected to a series-compensated transmission line. The DFIG converters control systems are well-known for their capability of mitigating power system oscillations such as SSR and inter-area oscillation.In this paper an auxiliary SSR damping controller (SSRDC) is designed for DFIG grid-side converter (GSC) using the hybrid big-bang big crunch (HBB-BC) algorithm. The HBB-BCalgorithm is one of the most recent powerful and efficient heuristic tools which in addition to its high precision and easy implementation, has a quite well convergence rate. The SSRmitigation capability of the designed controller including the induction generator effect (IGE) as well as the torsional interaction (TI) is evaluated by time domain simulations in MATLAB/Simulink. The performance of the proposed damping controller is approved for SSR attenuation by simulation results.

Sub-synchronous resonance; doubly-fed induction generator; series compensation; damping controller design; hybrid big-bang big crunch algorithm