Sliding mode control of PMSM based on a novel disturbance observer

Abstract

Conventional PI regular is a simple control method that is widely applied in permanent magnet synchronous motor (PMSM) control systems. However, in most cases, it cannot meet the requirements of high performance control. In order to improve system robustness and response, this paper adopts sliding mode variable structure control strategy in the design of a double-loop controller (speed loop and current loop). Integral compensation and disturbance observer are also introduced to prevent the possible steady-state errors and the intrinsic chattering. As to the different rotational inertia due to load changes, discrete model reference adaptive theory is adopted, which identifies the rotational inertia online and updates it to the observer. Experiments are carried out with a dSPACE real-time system. Experimental results demonstrate that the designed controller in this paper enhances system robustness and ensures good dynamic and static performances.