Research on Sliding Mode Control Strategy of VIENNA Rectifier in Front Stage of High Stability Magnet Power Supply

Abstract

Aiming at the problems of VIENNA rectifier with traditional double closed-loop PI control strategy, such as large output voltage ripple, poor anti-interference ability and large THD content at AC terminal, etc. A double closed-loop sliding mode variable structure control strategy is proposed. The outer loop is based on sliding mode variable structure control, and the calculation of the input reference current of the inner loop is simplified by using the power balance principle; The current inner loop adopts the direct sliding mode variable structure control method, and outputs the command voltage to the SVPWM module to complete the system control. Matlab/Simulink software is used for simulation verification, and the results show that compared with the traditional double closed-loop PI control strategy, the double closed-loop sliding mode variable structure control strategy significantly improves the dynamic performance and robustness of the system.