Improved Sliding Mode Control for Permanent Magnet Synchronous Motor Speed Regulation System

Abstract
Due to advantages such as high speed, high accuracy, low maintenance and high reliability, permanent magnet synchronous motor (PMSM) servo systems have been employed in many fields. In some cases, for example, speed fluctuations caused by load mutation would restrict the control stability, thereby limiting the usefulness of PMSM in high-precision applications. The speed regulation problem of PMSM servo control systems is discussed in this paper. A sliding mode disturbance control is developed in the vector control system to improve tracking performance of the PMSM system in order to suppress the speed fluctuations. The integration of sliding mode control and the proportional plus integral (PI) control can improve the performance of the closed-loop system and attenuate disturbances to a great extent. The proposed method can effectively improve the robustness and response speed of the system. Simulation and experimental analyses are conducted to demonstrate the superior properties of the proposed control method.