Disturbance-Observer-Based Second-Order Sliding-Mode Position Control for Permanent-Magnet Synchronous Motors: A Continuous Twisting Algorithm-Based Approach

Abstract

This paper proposes a novel composite position controller for the field-oriented control (FOC) strategy of permanent-magnet synchronous motor (PMSM) servo systems. The proposed composite position controller integrates a position controller with a disturbance observer, with each designed based on a specific second-order sliding-mode algorithm. Specifically, the continuous twisting algorithm (CTA) is employed to develop the position controller for achieving rotor position tracking, while the modified super-twisting algorithm (STA) is used to construct the disturbance observer for compensating the total disturbance in the rotor position tracking error dynamics to enhance the dynamic performance. Comparative simulation tests, conducted within an FOC strategy of PMSM servo systems, contrast the performance of the CTA-based position controller, the composite position controller using a CTA-based position controller and a standard STA-based disturbance observer, and the proposed composite position controller. The simulation results validate the proposed position controller’s effectiveness and its superiority over comparable position controllers.

Keywords

• disturbance observer
• permanent-magnet synchronous motor
• servo system
• position control
• sliding-mode control
• sliding-mode observer