Nonlinear disturbance observer based robust tracking control for a PMSM drive subject to mismatched uncertainties

A robust nonlinear disturbance observer based control (NDOBC) approach is proposed for a permanent magnet synchronous motor (PMSM) drive system which is supposed to experience mismatched parameter perturbations as well as unknown load torque disturbances. The proposed control method is expected to obtain fine robustness against parameter uncertainties and external disturbance attenuation performance since it takes into account the full nonlinear dynamics, all possible parameter perturbations, and also the external disturbances in the PMSM system. The final simulation studies and results demonstrate that the proposed method obtains prominent robust tracking performance in the presence of mismatched uncertainties.