Enhanced One Degree-of-Freedom ADRC With Sampled-Data Iterative Learning Controller for PMSM Uncertain Speed Fluctuations Suppression

The permanent magnet synchronous motor (PMSM) control system is expected to output a smooth and stable speed even in the presence of uncertain periodic and aperiodic disturbances. To accomplish this goal, an enhanced one degree-of-freedom (DOF) active disturbance rejection controller (ADRC) with sampled-data iterative learning controller (ILC) is proposed for the speed loop of PMSM drives to suppress the uncertain periodic and aperiodic disturbances. First, through a comparative analysis of two recently proposed 1-DOF ADRC schemes, a scheme with superior dynamic response and anti-disturbance performances is chosen for deployment as the PMSM speed controller. It retains the anti-disturbance performance of the traditional 2-DOF ADRC to the aperiodic disturbance. Then, in response to its limited effectiveness in attenuating uncertain periodic disturbances in the speed loop, the sampled-data ILC is used to improve the anti-disturbance performance of the 1-DOF ADRC to uncertain periodic disturbances. Thus, the proposed scheme can suppress both uncertain periodic and aperiodic disturbances. Therefore, the proposed scheme can be employed as the speed controller in PMSM drives to attenuate the uncertain periodic and aperiodic speed fluctuations and improve the speed control accuracy. In addition, the convergence of the proposed scheme is analyzed in the frequency domain, and its conclusions can be used to guide parameter tuning. Finally, the effectiveness of the studied scheme is validated on a 2.2-kW PMSM platform.