Resilience of Grid-Connected Wind Farm Using a Flexible Asynchronous AC Link

This paper presents an integration of wind farm (WF) into the utility grid through the flexible asynchronous AC link (FASAL) to achieve better resilience and mitigate power fluctuations. An equivalent aggregated squirrel cage induction generator (SCIG) based WF of 200 MW connected to a 150 kV utility grid through FASAL is considered for performance evaluation under LLLG fault conditions using PSCAD/EMTDC based simulation. Moreover, a comparison of the performance of the FASAL system and AC link for the connection of WF is made under grid fault conditions. Under LLLG fault, the AC link experiences significantly high fluctuations and overshoots in real and reactive power, electromagnetic torque, which causes stress on the wind turbine and the gearbox. It is found that the fluctuations and overshoots are small in the real and reactive power, electrical frequency of WF, and the electromagnetic torque in the case of the FASAL system. Thus, the FASAL shows better resilience as it reaches the normal operating condition faster with fewer oscillations. Moreover, the adverse effects of the LLLG fault on the wind turbine and the gearbox are also found small.