Sub-synchronous resonance mitigation in wind farms using gate-controlled series capacitor

The increasing deployment of wind power generation is leading to the integration of large wind farms into the power distribution grid. Given the remote geographic location of wind farms, series capacitive compensation is commonly used to ensure stable power transmission over long distances. However, the sub-synchronous resonance (SSR) phenomenon presents potential risks in a series compensated wind farm. Although the SSR problem in traditional power systems is well-known and has been extensively studied in the literature, the SSR problem in series-compensated wind farms requires more study and analysis. This paper investigates the application of the gate-controlled series capacitor (GCSC), a new series FACTS device consisting of a fixed capacitor in parallel with a pair of anti-parallel GTOs, for series compensation in fixed-speed wind turbine generator (FSWTG) systems. The GCSC enables fast control of series impedance of the transmission line, which can be used for SSR damping. The power system studied in this paper is the IEEE First Benchmark Model. Extensive simulations are carried out using PSCAD/EMTDC to validate the result. Simulation results show that the GCSC can effectively damp the SSR in wind farms. Therefore, the GCSC is an effective solution to provide series compensation and SSR damping for the FSWTG.