A Circulating Current Suppression Method for Dual-Input Converter With Integrated Mismatch Power Processing Unit

The dual-input converter with integrated mismatch power processing unit (MP²U) can effectively eliminate the limitation of power transmission capability caused by pulse width modulation (PWM) control. However, its considerable circulating current increases the loss of switches and limits the improvement of its efficiency. In this article, a circulating current suppression method (CCSM) is proposed. By changing the inner phase shift angle of the integrated MP²U, the extra operating state of the MP²U can be used, and the working state sequence of the MP²U is reconstructed to change the current waveform in the MP²U. The proposed CCSM control can completely eliminate the circulating current when the two input ports are matched and greatly suppress the circulating current when the two input ports are mismatched, achieving the overall efficiency optimization of the dual-input converter. In addition, the optimized inner phase shift trajectory of the proposed CCSM control under different mismatch conditions is calculated, and the soft switching operation of all switches in MP²U is ensured. The proposed control method is verified by the experimental results of a 500 W prototype.