MHz-Driven Snubberless Zero-Current Soft-Switching High Step-Up DC-DC Converter with a Multi-Resonant Tank

Abstract

A novel high step-up DC-DC converter suitable for the power interface of fuel cells is presented in this paper. The proposed converter features a multi-resonant tank for achieving high-step up ratio under zero current soft switching (ZCS) without any snubber circuits. The simple and minimized-component topology is beneficial for Mega-hertz driving of Gallium Nitride (GaN) power transistors with effective reductions of switching loss, electromagnetic emission interference (EMI) noise, and ripple-free DC input current. Mode-transitional power stages are described in detail, following that the high step-up principle is revealed by means of frequency-domain analysis. The essential performances of the proposed circuit topology are demonstrated by simulation and experiment of 1.8MHz-120W prototype whereby effectiveness of the snubberless and multi-resonant topology are verified from the practical point of view.