Optimum power control strategy for SEIG-based variable speed WECS

Self-excited induction generators (SEIGs) have a significant potential for application in small scale wind energy generation systems due to their robustness, lower cost and lower maintenance requirements. This type of generator is often incorporated with variable speed wind turbines where maximum power extraction is possible. In such applications, SEIG is intensively used with full-sized converter configurations. Maximum power point tracking is a critical element of converter control to optimize power extraction from wind. In contrast to photovoltaic applications, many tracking algorithms in wind turbines face difficulty in handling rapid and high wind speed fluctuations. This paper presents an optimum control strategy for a SEIG based small-scale wind energy generator coupled to the grid through a buck-boost inverter. It combines two control strategies to minimize the time needed to reach the maximum power point of the generator under varying wind speeds. The computer simulation results confirm that the proposed controller outperforms traditional maximum power point controllers.