A high power medium voltage resonant dual active bridge for DC distribution networks

摘要

This paper presents a megawatt scale, medium voltage, medium frequency resonant dual active bridge dc-dc converter operating as a bus-tie converter in a dc distribution network. The high voltage side of the converter is designed using series connected low voltage devices in order to efficiently operate at higher switching frequencies. A combined variable frequency and phase shift control method is proposed to achieve input/output power flow and voltage control, while maintaining soft switching operation for both high voltage and low voltage bridges. A 1MW converter prototype is presented to validate the proposed topology and control.