Rotor Position-Sensorless Algorithms for Direct Power Control of Rotor-Tied DFIG

In this letter, direct power control (DPC) of rotor-tied doubly fed induction generator (DFIG) is presented for the first time. First, a theoretical study is presented to acknowledge the fundamentals of DPC of rotor-tied DFIG. Thereafter, two rotor position-sensorless algorithms (RPSAs) are presented to eliminate the need of rotor position sensor. The RPSA-I is developed using the mathematical model of rotor-tied DFIG and necessitates at least four current sensors. The RPSA-II is evolved with the requirement of only two current sensors and, consequently, get rid of complex computations from the algorithm. In addition to this, it is independent of all the machine parameters and stable at or near synchronous speed. Finally, the proposed scheme is tested by real-time implementation of DFIG-based wind energy conversion system under the dynamic wind speed conditions.