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 (MP<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>U) 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 MP<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>U, the extra operating state of the MP<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>U can be used, and the working state sequence of the MP<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>U is reconstructed to change the current waveform in the MP<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>U. 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 MP<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>U is ensured. The proposed control method is verified by the experimental results of a 500 W prototype.