Impact of wind turbines equipped with doubly-fed induction generators on distance relaying

Wind generation is evolving from single wind turbines to wind power plants with an installed capacity of tens of megawatts. Therefore, wind turbines are also coupled to the transmission grid instead of the distribution grid. Problems arise during grid faults as the behaviour of wind turbines equipped with doubly-fed induction generators differs fundamentally from traditional synchronous generators. The short-circuit behaviour is vital for protection issues. A distance relaying problem in a Belgian grid topology is emphasized and studied. This study concludes that the distance relay is not performing correctly in case of three phase faults. Moreover, varying parameters such as the crowbar resistance and the wind turbine loading have a significant impact on the relay performances.