Development of Phase-Shift Full-Bridge Converter With Integrated Winding Planar Two-Transformer for LDC

This study proposes a new phase-shift full-bridge (PSFB) converter with an integrated winding planar two-transformer for a low-voltage dc-dc converter (LDC). An LDC is a dc-dc converter that supplies power to a 12-V auxiliary battery (A_BAT) and loads from the main battery (M_BAT) of electric vehicles (EVs), used in low-voltage and high-current output applications. PSFB converter is widely used as a suitable topology for such systems. In order to improve the power density, the integrated planar magnetics is designed in the proposed PSFB converter. Furthermore, the size of the transformer is optimized considering the footprint and core loss of components. To confirm the validity of the proposed converter, a 2.1-kW prototype LDC with an input voltage range of 400-800 V and an output voltage of 14 V is analyzed, and the operating characteristics are described. The proposed converter achieves a maximum efficiency of 95.4% and a power density of 5.2 kW/L.