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 (FC) 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 megahertz 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 1.8 MHz‐120W prototype whereby effectiveness of the snubberless and multi‐resonant topology are verified from the practical point of view.