Three-port DCX-based High Step-down DC-DC Converter

A high step-down DC-DC converter based on a three-port DC transformer (DCX) is proposed. A power flow path from the input port to the load port and a power flow path from the input port to the intermediate DC bus port are built using a three-port DCX. Voltage regulation of the load port is achieved using a Buck converter connected between the intermediate DC bus and the load port. Single- and two-stage hybrid power conversion structures are built using a high step-down DC converter. Part of the power is processed by a DCX through single-stage power conversion. The circuit topology, operating principle, and characteristics of the high step-down DC-DC converter are presented. A detailed analysis of the transformer and autotransformer in the three-port DCX is presented, and the transformer and autotransformer are implemented with an integrated planar magnetic core and PCB windings. The design considerations for the proposed converter are also discussed. The effectiveness and feasibility of the proposed converter are verified experimentally.