A Robust Encoderless Predictive Current Control Using Novel MRAS Observer for Surface-Mounted Permanent-Magnet Synchronous Generators

Abstract:
This paper proposes a robust encoderless predictive control strategy for variable-speed wind turbines (VSWTs) with permanent-magnet synchronous generator (PMSG). The proposed predictive control is based on the deadbeat (DB) scheme, which has a good transient response but it requires the full knowledge of the system parameters. To overcome such a limitation, a discrete time integral action (DTIA) is added to the DB algorithm in order to increase the robustness against parameter variations and achieve a good steady-state response. The proposed DTIA is simple and easy to implement. Furthermore, a novel model reference adaptive system (MRAS) observer is presented for estimating the rotor speed and position of the PMSG. A search algorithm based on the finite control setmodel predictive control (FCS-MPC) concept is utilized to replace the fixed-gain PI controller in the adaptation mechanism of MRAS observer. Experimental results are presented to illustrate the feasibility of the proposed control strategy and observer under different operation conditions and under variations of the PMSG parameters.