Integrated magnetics design for a full-bridge phase-shifted converter

Abstract

Full-bridge phase-shifted converters sometimes add external resonant inductors to achieve zero-voltage switching during light load conditions. The magnetic components in the circuit include a resonant inductor, transformer, and output inductor. These magnetic components occupy a sizable portion of the circuit volume, which results in low power density. To achieve higher power density, this paper analyzes the magnetic integration of these three magnetic components into one core. This analysis derives the flux density and output ripple current by calculating the dc-ac flux and equivalent output inductance during operation intervals. The resonant inductor in the traditional full-bridge phase-shifted converter is replaced by adjusting the distance between primary-side winding and secondary-side winding. Finally, the prototype of a 500-W full-bridge phase-shifted converter which operates with 380-V input voltage and 12-V output voltage is implemented using integrated magnetic technology.