Output voltage ripple reduction control strategy for three-phase combined PFC converter under grid voltage unbalance

The combined three-phase single-stage PFC converter is a promising topology in high-power applications. However, the output voltage ripple present under grid imbalance severely affects the output characteristics of the converter. Based on this, this paper analyzes the topology and conventional control strategy of the combined three-phase single-stage PFC converter. The problem of large output voltage ripple under the condition of unbalanced input voltage is theoretically analyzed, and the corresponding ripple suppression control strategy is proposed. The operating characteristics of the system under the control strategy proposed in this paper are analyzed. Finally, the correctness of the theory and the effect of power factor correction are verified by PLECS simulation and construction of the experimental platform. The results show that the proposed control strategy is an effective method to solve the output voltage ripple problem of the combined three-phase PFC converter and the power factor correction effect is good.