A Low Loss Orthogonal Decoupling Magnetic Integrated Structure for Dual Active Bridge Converter

The volume of magnetic components (transformer and inductor) in a dual active bridge (DAB) converter is a crucial factor determining its power density. This article proposes an orthogonal decoupling magnetic integrated structure (ODMIS) for DAB converter, which aims to reduce the volume of the transformer and inductor. The integrated series inductor and magnetizing inductor do not affect each other in the ODMIS, so the design process of the transformer and inductor can be separated. The condition to realize magnetic circuits decoupling of the transformer and inductor is derived. The loss characteristics of the magnetic core are analyzed, and the optimal decoupling condition to minimize the core loss is also derived. A 400 V/6 kW/20 kHz DAB converter prototype is built to validate the effectiveness of the ODMIS. The measured full-load overall efficiency of the DAB test platform is 97.55%, and the power density of the magnetic integrated components is 10.08 kW/L. Finally, the prototype comparisons between the proposed ODMIS and two existing magnetic integrated structures and discrete magnetic component method are conducted, and the advanced feature of the ODMIS is illustrated.