Robust speed control of a permanent magnet synchronous motor system

In this paper, a sliding mode controller (SMC) and a linear active disturbance rejection controller (LADRC) are applied to a permanent magnet synchronous motor (PMSM) respectively for speed control. PMSM is a major part of electric drive systems. It has its inherent problems of nonlinearity, coupling, and structured uncertainties, and is subject to external load disturbance. Both LADRC and SMC can successfully drive the speed output of a PMSM to a reference signal despite the presences of uncertain dynamics and unknown disturbance. Simulation results verify the effectiveness and robustness of the LADRC and SMC. The speed control performances of both controllers are compared with each other. The comparison study shows that the SMC is superior to LADRC in being robust against parameter variations while the LADRC is better than SMC in disturbance rejection.