Discrete-Time Improved Equivalent-Input-Disturbance Control with Dynamic Decoupled Adaptive Damping Regulator for PMSM Current Enhancement

Conventional motor drives are subjected to extensive disturbances and uncertainties across entire frequency spectrum, which significantly deteriorate current control performance within electric propulsion system. To address this issue, this paper proposes a discrete-time composite control strategy that integrates an improved equivalent-input-disturbance (IEID) approach with a dynamic decoupled adaptive damping (DDAD) regulator, aiming to suppress external disturbances and improve the transient current response. Specifically, a proportional-integral augmented observer (PIAO) is introduced into the IEID framework, where the integral of the measured current is treated as an augmented variable. This modification enhances both the estimation accuracy of internal states and the system’s resilience to the current measurement noise. Furthermore, a modified causal filter, constructed building upon an integral-resonant internal model structure, is incorporated into the IEID estimator to achieve simultaneous and effective attenuation of both disturbances and harmonics. Finally, an improved adaptive damping function that is adjustably updated with load current as well as motor speed and the associated dynamic decoupled control law are systematically designed using poles placement techniques, enabling the superior transient dynamics and the flexible damping characteristics. Comparative experimental results validate the practical applicability of the proposed control method.