System-in-magnetics based compact dab converter module with leakage-integrated high-frequency transformer and co-packaged SiC MOSFETs

This work presents a compact and unified dual-active-bridge (DAB) converter module enabled by a system-in-magnetics (SiM) structural concept featuring a hexagonal high-frequency transformer (HFT) and co-packaged SiC MOSFETs. Unlike conventional DAB or resonant CLLC converters that require bulky auxiliary inductors and multiple discrete passive components, the proposed architecture eliminates external inductors entirely by precisely controlling the HFT’s leakage inductance through strategic core placement and adjustable winding gaps. Instead of employing large, heavy, and expensive core pairs, the HFT is constructed using multiple small, lightweight, and cost-effective U26/22/16 ferrite cores in a hexagonal configuration. This geometry enables tunable leakage inductance through adjustable segment spacing and provides a central hollow region that accommodates the entire electronic system, resulting in a compact and unified DAB converter module. The HFT design is validated through COMSOL magnetic simulations, confirming the effective integration of leakage inductance for DAB converter operation. Finally, a physical prototype of the SiM-based DAB module has been fabricated, incorporating the hexagonal HFT along with co-packaged SiC MOSFETs, thermal management elements, the controller, gate drivers, and the main PCB within a single consolidated package. Experimental testing verifies the effective operation, feasibility, and advantages of the proposed architecture for versatile bidirectional power management applications.