Stabilization of wind farms by DFIG-based variable speed wind generators

Recent wind farm grid codes require wind generators to ride through voltage sags, which means that normal power production should be re-initiated once the nominal grid voltage has been recovered. This paper proposes a new control strategy using DFIGs (Doubly Fed Induction Generators) for stabilizing a wind farm composed of DFIGs and IGs (Induction Generators). Simulation analysis by using PSCAD/EMTDC shows that the DFIGs can effectively stabilize the IGs and hence the entire wind farm through the proposed control scheme by providing sufficient reactive power to the system.