A Novel DCX Based on ZVZCS Full-Bridge Cells with Voltage-doubler Rectifier for DC Grids

This paper proposes a high power dc transformer (DCX) suitable for dc grids, containing two full-bridge cells in series connection both in input and output side. The proposed DCX uses a special but simple control strategy to enable it to work in discontinuous conduction mode, which can realize zero current switching for the main full-bridge cell in the whole load range. Consequently, the switching loss is reduced and the system efficiency is improved. The performance is verified by the simulation model established in the software PLECS.