GaN-Based 1-MHz Partial Parallel Dual Active Bridge Converter With Integrated Magnetics

In this article, a partial parallel dual active bridge (PPDAB) converter is proposed to lower the current stress over switching devices on low-voltage side. Gallium Nitride (GaN) transistors are used improve efficiency and power density at 1 MHz frequency. Moreover, in order reduce number of magnetic components achieve more compact design, with unique three-leg core geometry, new method integrating three transformers their associated interfacing inductors proposed. The integration able shorten winding length therefore reduces dc resistance. wounding secondary windings each outer leg enlarges leakage inductance, which can serve as inductor L ac PPDAB converter. Given that, reluctance model analyze coupling effect well balance derived validated by finite element simulations. Based both calculations simulations, integrated transformer found be functionally equivalent discrete transformers, primary connected series, additional inductor. Additionally, given same turns module, ac currents these inherently balance. Finally, fully GaN-based 1.2-kW 1-MHz 400V/50V prototype peak 97.51% built tested verify theoretical analysis.