ZVS-Oriented Power Sharing Control in Modular DAB Converters Connected in Input-Parallel Output-Parallel Configuration

This paper presents an analytical formulation, implementation and validation of an intelligent load sharing algorithm capable of enhancing the zero-voltage-switching (ZVS) performance, applicable to an input-parallel output-parallel (IPOP) connected dual-active-bridge (DAB)-based modular dc-dc converter system. In this study, first, the critical inductor currents required to attain ZVS in the DAB switching legs are identified based on the non-linear body capacitor <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(C_{oss})$</tex> of the switching devices, followed by synthesis of the critical ZVS power conditions. Then, the total system load is intelligently distributed among the DAB modules so that all the modules can independently experience soft-switching under any gain and load scenario. The proposed load sharing algorithm promises to showcase significant efficiency (~0.5-2%), and EMI benefit in DABs in IPOP configuration.