Load-Source Matching with Dielectric Isolation in High Frequency Switch Mode Power Supplies

Abstract

This paper presents a new hybrid passive power device, denoted as the hybrid transformer, which is an improved alternative to the classical two-winding high-frequency transformer (100's kHz–MHz). The hybrid transformer is comprised of a coupled inductor topology, that provides load–source matching, denoted as the mutual branch topology, and a dielectric isolation device denoted as the multilayer capacitive isolation device. The main focus of this paper is on the design and operation of the mutual branch topology. Simulation results are shown to highlight the improved efficiency of the hybrid transformer over a conventional high-frequency transformer. Finally, the efficiency of the hybrid transformer is compared with that of a classical two-winding transformer using the same resonant converter, highlighting the improved efficiency of the hybrid transformer (up to 10% improved efficiency for light loads).