Critical Current-Constrained Continuous Nonsingular Terminal Sliding Mode Control for PMSM Based on Control Barrier Function

Abstract

In this paper, the speed regulation control problem for permanent magnet synchronous motor (PMSM) under the single-loop control structure is investigated. Specifically, certain issues, such as the risks of over-current and multi-source disturbances, can increase the likelihood of damage to the system circuitry and lead to unsatisfactory speed regulation performance. To tackle these issues, a current-constrained continuous nonsingular terminal sliding mode control (CNTSMC) approach via the control barrier function (CBF) technology is proposed. First, a nonlinear finite-time extended state observer is constructed to estimate the unmatched disturbances in PMSM systems. Subsequently, a new composite CBF-based CNTSMC method incorporating the disturbance estimation is designed, such that the undesirable influence of multi-source disturbances on the control performance can be effectively attenuated, while guaranteeing strict current constraints. Finally, the stability analysis of the closed-loop control system is presented. Comparative experimental results demonstrate that the proposed method achieves better speed regulation and critical current constraint performance even in the presence of unmatched disturbances.