Study of the factors affected the rotor over-current of DFIG during the three-phase voltage dip

Abstract

Doubly Fed Induction Generators (DFIG) becomes quite common employed in the wind farms. But the main disadvantage of DFIG is that it's very sensitive to grid disturbance, especially for the voltage dip. It could cause over voltage and over current in the rotor windings and consequently damaged the rotor side converter. In this paper, the author first made a theoretical analysis to the rotor current based on the model of DFIG. Then according to the analysis, the reasons of caused the inrush current and the factors affected the dynamic behaviors of DFIG were proposed. Some methods constrained the rotor over-current were briefly introduced with respected to the factors mentioned above. At last, the response of the doubly fed induction generator wind turbine system to grid disturbances was simulated and the matlab/simulink simulation results verified the factors proposed in the paper were the key points affected the performance of DFIG during the stator terminal voltage dip.