A modified sliding-mode controller-based mode predictive control strategy for three-phase rectifier

In three-phase pulse width modulation rectifiers, proportional integral (PI) has been used in voltage outer-loop to obtain the active current reference when using the conventional model predictive control strategy. However, the performance of the dynamic response is poor as large step and longer settling time are required on the active power under the load variation. To cope with this problem, a sliding-mode controller can be employed to replace the PI controller. Nevertheless, the sliding-mode variable structure control is discontinuous which leads to the chattering problem. In this work, a novel control strategy which combines a simplified model predictive control and a modified sliding-mode control is proposed and investigated. The proposed strategy is supposed to reduce the effect of unexpected disturbances such as the DC-link voltage step and the load variation. Simulation and experiments have been conducted for validation. The results indicate that the proposed strategy is feasible and has excellent dynamic response. Furthermore, it is easy to design and implement.