A High Power Medium Voltage Resonant Dual Active Bridge for MVDC Ship Power Networks

This paper presents the design and control of 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 (HV) side of the converter is designed using series connected low voltage (LV) devices 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 the HV and LV bridges. Two 1 MW converter prototypes operated in a back-to-back arrangement are presented to validate the proposed topology and control.