Control Strategies for Brushless Doubly Fed Reluctance Generator in WECS: Review

With two electrical ports and one mechanical port, the brushless doubly fed machine (BDFM) has more speed and power control degree of freedom, high reliability and inherent fault tolerance capability compared with conventional singly fed machine. Recently, the BDFM has been proposed as a talented alternative for the conventional doubly fed machine. This paper is concerned with using the Brushless Doubly Fed Reluctance Generator (BDFRG) in wind power applications. The BDFRG has additional advantages when compared with conventional counterparts. Rather than dive into details, a historical review on the BDFRG and its principle of operation is presented to understand the theory of operation. This paper also introduces the modelling equations in d-q frame and space phasor. This paper focuses on the different control techniques used with BDFRG in literature to extract maximum power from wind and control the machine power factor to show how would this machine be a suitable alternative generator in wind applications.