Optimized Synchronous Operation of Active-Clamp Bidirectional Flyback based on GaN Devices for a Multi-cell Multi-port Structure

Abstract

This work proposes an optimized synchronous operation of bidirectional active clamps for the novel Multi-cell Multiport Bidirectional Flyback (M2BF). Active-clamp circuits in both sides enable zero-voltage switching in all transistors, minimizing switching losses. Moreover, this work presents an optimization of transistors gates sequence based on an intervals estimator to have fully synchronous operation in the secondary transistors and to reduce free-wheeling conduction losses, specially critical in GaN-based converters. Power losses can be reduced by 40%, resulting in high-efficiency solution for an output power of 120 W. Experimental measurements with a GaN-based prototype validate the proposed method.