Disturbance-observer-based speed control for SPMSM drives using modified super-twisting algorithm and extended state observer

To address the robust speed control problem of the surface-mounted permanent-magnet synchronous motor (SPMSM) drive, a novel composite speed controller (CSC) is proposed, which consists of the modified super-twisting sliding-mode SC (STSM-SC) and the extended state observer (ESO). Regarding the motion dynamics of the SPMSM drive, the unmodeled dynamics, endogenous, and exogenous disturbances are lumped together as the total disturbance. The ESO-based feedforward compensation mechanism is used to deal with the total disturbance for the robustness improvement of the speed control achieved by the modified STSM-SC-based feedback regulation mechanism. On the basis of the field-oriented control strategy, performance comparisons of the standard STSM-SC, the ESO-based standard STSM-SC, the modified STSM-SC, and the proposed CSC are carried out on a suitably developed experimental setup. The experimental results are presented to validate the superiority of the proposed CSC.