Implementation of Active-Clamped Flyback DC-DC Converter in an 800 V System

In this paper, design and implementation of the active-clamped flyback (ACF) dc-dc converter powered from the 800 V variable dc-link, are presented for the first time. The 57 W prototype was built and tested with two different transformers and resonant tanks. Maximum efficiencies at 620 V and 850 V inputs were 86% and 83.5%, respectively. Those resulting efficiencies are comparable with efficiencies of the classical Flyback dc-dc converter. Nevertheless, the ZVS operation and reduced EMI justified usage of the ACF, rather than classical flyback converter, for this application. In addition, suggestions were made on how to improve control ICs features for future applications of ACF in the 800 V systems.