Zero-Voltage Zero-Current Transition Network for Dual-Phase Interleaved Converter

In this article, a zero-voltage zero-current transition scheme suitable for a family of dual-phase interleaved converters is proposed. The transition network consists of an auxiliary transformer, a switch, and a clamp diode. This network uses a low component count structure, and yet achieves effective soft-transitions (zero-voltage turn-ON as well as zero-current turn-OFF) for the main switches. It facilitates zero-current turn-OFF of all the diodes along with zero-current turn-ON of the auxiliary switch. Additionally, the auxiliary transformer self-adjusts the current in the auxiliary network depending upon the loading conditions and thus the reactive energy during the soft-switching is low for the entire range of loads. A detailed theoretical analysis is presented by considering a high step-up dual-phase interleaved boost converter as an example. The feasibility of the proposed soft-switching scheme is implemented on the same and its effectiveness is demonstrated through experimental results which are obtained on a 400-W converter prototype.