Control strategy of large-scale DFIG-based wind farm for power grid frequency regulation

With the integration of large-scale wind farm, the frequency security of power grid may be impacted due to the lack of frequency regulation support from wind turbines which caused by the traditional decoupling control system. In order to enable doubly fed induction generator (DFIG) wind turbine to participate in the power grid frequency regulation, active power output of the wind turbine should be controlled with request. A control strategy to regulate active power output for DFIG has been proposed in this paper. Once the DFIG is controlled at the deloading operation condition with some power reserves, the rotor kinetic energy together with the power reserves can be well used to support the system frequency regulation. Simulation results have shown the frequency control effect and the behaviors of the DFIGs with such frequency control strategy, validating the feasibility and the effectiveness of the proposed control strategy.