Design of Planar Transformer for Dual Active Bridge for Renewable Energy Sources and Grid Integration Applications

The increasing integration of Renewable Energy Sources (RES) with smart sensing devices, advanced control, and integrated communication in smart grid has surged the motivation towards improving power density, efficiency, and reducing the size/weight of power converters. This has shifted the focus on planar magnetics as components such as inductor, transformer account for major share of losses and volume in a converter. Planar magnetics replace the traditional wire-wound structure with windings on Printed Circuit Board (PCB), or using thin copper sheets resulting in low profile and high power density. The design of a planar transformer for Dual Active Bridge (DAB) for RES and grid integration applications is discussed in this paper. Multi-objective optimization is conducted with objectives of reducing losses and overall volume of DAB with a planar transformer. A planar transformer hardware prototype for DAB was constructed and tested to demonstrate transformer performance and advantages of this design approach.