Reactive power control of doubly fed induction generator in wind farm under low grid voltage

This paper calculates the reactive power limit of DFIG (doubly fed induction generator), and discusses the current reactive power control schemes of DFIG. Three methods, which use both the grid and rotor side converters for voltage regulation and reactive power support, are analyzed and compared. This paper presents a new coordinated control strategy, which central idea is to use the grid-side converter as the main reactive power controller and the rotor side converter as auxiliary. The new presented control scheme is modeled on MATLAB/SIMULINK, and the results show the effectiveness of the proposed control scheme. Providing reactive power to grid can assist the recovery of the grid voltage.