An Improved Vector Control Strategy for Switched Reluctance Motor Drive Based on the Two-Degree-of-Freedom Internal Model Control

Abstract

The unipolar sinusoidal current excited control strategy of the switched reluctance motor (SRM) has been widely attended for its wide driving area and acceptable torque ripple. However, due to the SRM’s time-varying, non-linear, and high coupling features, the traditional vector control strategies are unable to provide excellent current control performance. In this paper, a novel vector control method based on a two-degree-of-freedom internal model control (2DOF IMC) is proposed. The main objectives of this article are to improve the control precision and to enhance the system’s robustness. Firstly, considering the non-linear characteristics of the system in the rotating reference frame, a 2DOF IMC controller based on a simplified SRM model is designed and the stability analysis of the controller is implemented. Since the time-varying disturbance cannot be effectively eliminated using the 2DOF IMC with constant filter parameters, a simple adaptive disturbance observer (ADO) is incorporated into the inner-loop system to online estimate and eliminate these disturbances. Moreover, a stability analysis based on Lyapunov theory is also presented, and the ADO’s stability and convergence are guaranteed by tuning the adaption gain law. Finally, the effectiveness of the proposed control strategy is demonstrated by experiments, and the results illustrate that the proposed method can effectively improve the control and disturbance rejection performance of the SRM drives.