An Improved Adaptive Sliding Mode Speed Control of PMSM Drives With an Extended State Observer

Aiming at the application occasions that require high dynamic performance of the drive motor speed controller, this paper proposes an adaptive sliding mode control (ASMC) with an extended state observer (ESO) to enhance the speed control performance of the permanent magnet synchronous motor (PMSM) against internal and external disturbances. Firstly, a new adaptive reaching law (ARL) is proposed, which can suppress the chattering effectively and reduce the convergence time of the system state. Based on ARL, the proposed ASMC for speed control of PMSM drives is developed, combined with an integral-type terminal sliding mode surface. Furthermore, by introducing the nonlinear term into the sliding mode control scheme, the convergence velocity to the equilibrium is improved and the finite-time convergence is guaranteed. Secondly, an ESO is developed to estimate the lumped disturbance for feedforward compensation and update the control algorithm of ASMC. The proposed ASMC+ESO control method enhances robustness against disturbances while maintaining fast dynamic response and high tracking accuracy. Finally, the proposed controller is implemented on a 0.4 kW PMSM test platform and the results confirm the validity.