Complementary extended state observer-based model-free sliding mode control for a PMSM in cathode copper production

This study introduces a model-free sliding mode control scheme based on a complementary extended state observer (CESO) for a permanent magnet synchronous motor (PMSM) in cathode copper production. First, an ultra-local model of the PMSM is proposed. Compared with the existing ultra-local model, the ultra-local model proposed in this study divides the disturbances into periodic and aperiodic perturbations. Furthermore, based on the proposed ultra-local model, a CESO is proposed. Compared to the linear extended state observer (LESO) and the non-linear extended state observer (NLESO), the proposed CESO combines the advantages of the LESO and the NLESO. The proposed CESO exhibits reduced disturbance estimation errors and greater resilience to significant periodic and minor aperiodic disturbances. By leveraging the ultra-local model, a novel combined control strategy is devised, utilizing the CESO and a model-free sliding mode control. The stability of the proposed control scheme has been verified through the Lyapunov stability theorem and the Hurwitz stability criterion. Subsequently, comparative simulations on disturbance rejection are conducted under periodic and aperiodic disturbances, illustrating the efficacy of the proposed control approach.