Sliding Mode Predictive Current Control of Permanent Magnet Synchronous Motor With Cascaded Variable Rate Sliding Mode Speed Controller

Abstract

To solve the problem that the conventional vector control system of permanent magnet synchronous motor is susceptible to motor parameters and load disturbances, a sliding mode predictive current control strategy of permanent magnet synchronous motor with cascaded variable rate sliding mode speed controller based on extended state observer (ESO) is proposed, which improves the dynamic and static performance of the system. First, a sliding mode speed controller is designed based on the novel variable rate exponential reaching law, and the ESO is used to estimate and compensate for parameter mismatch and disturbance, which improves the system’s rapidity and robustness while reducing the chattering. Then, to solve the problem that the traditional deadbeat predictive control of current loop ignores the influence of cross-coupling electromotive force, based on the above reaching law, a sliding mode controller is designed to equate the back electromotive force to effectively compensate the deadbeat predictive current controller, which not only retains the rapidity of current but also enhances the robustness. Finally, simulation and experimental results show the effectiveness of the proposed control strategy.

Keywords

• Permanent magnet synchronous motor
• deadbeat predictive current control
• sliding mode control
• extended state observer