An Efficient Interleaved Bidirectional DC–DC Converter With Shared Soft-Switching Auxiliary Circuit

A soft-switching interleaved bidirectional dc–dc converter, which is the combination of the conventional one and the introduced auxiliary circuit, is proposed in this article. The auxiliary branch composed of a capacitor, an inductor and two switches connected in series, is attached to the switching nodes of the two phases and serves them in a shared manner. Due to voltage continuity of the auxiliary capacitor, the zero-voltage switching (ZVS) condition is realized nearly for primary switches at turn-
off
. With the designed driving sequences, the current gradually flows through auxiliary inductor ahead of primary switches turn-
on
, which is key to realizing ZVS condition for the switches. Moreover, the limited current slope guarantees the zero-current switching condition for auxiliary switches. Operating principle in buck mode is elaborated and design guideline is presented. Considering the parasitic resonance between the auxiliary inductor and the output capacitors of auxiliary switches, a clamping structure is given. A 1.2-kW prototype of the proposed converter is built and tested. The experimental results show the high performance.