CBF-DOB-Based Current-Constrained Control for PMSM Systems Subject to Unmatched Disturbances

This article addresses the speed regulation problem of permanent magnet synchronous motor (PMSM) with overcurrent protection and time-varying disturbances. A novel safety-critical robust control algorithm is developed with control barrier function (CBF) and disturbance observers (DOBs). Two disturbance observers are first utilized to estimate lumped disturbances caused by external load torques and parameter uncertainties. Then, a safety-related CBF with disturbance compensation mechanism is designed to guarantee the overcurrent protection and robust performance of PMSM. Finally, the CBF-DOB based safe controller can be obtained by solving a quadratic program (QP) with the sliding mode control (SMC) integrated as a nominal controller. Numerical examples are extensively conducted to demonstrate the promising benefits of the proposed control method.