Finite Control Set Model Predictive Control for dc Voltage Balancing in Vienna Rectifier

This paper is concerned with the investigation of Finite Control Set Model Predictive Control (FCS-MPC) for dc link voltage balancing in a Vienna rectifier. Large EV charging stations with common dc bus utilize a high-power rectifier as a front end conversion stage. In this regards, Vienna rectifier, as a central ac-dc stage, with bipolar dc bus structure is an attractive choice. Bipolar dc bus is potentially prone to voltage imbalance which is undesirable. dc link voltage imbalance also lead to distorted input current and more power quality issues. This paper proposes a capacitor voltage balancing technique based on the FCS-MPC method. In order to apply the FCS-MPC method, the discrete time model of the Vienna rectifier in unbalanced conditions is derived. By applying this model, the proper cost function is proposed to balance dc bus voltage. Simulation and experimental results are presented to validate the proposed control strategy in terms of the effectiveness of output voltage balancing and low distortion input current.