Three‐Phase AC/DC Converter Based on Swiss Rectifier and Interleaved Three‐Rail LLC‐DCX With Only Front‐Stage Control

ABSTRACT This article proposes a two‐stage charging topology for automated guided vehicle (AGV), combining a front‐stage Swiss rectifier for wide‐range voltage regulation and a rear‐stage interleaved three‐rail LLC resonant converter acting as an isolated DC transformer (DCX). Unlike conventional boost‐type rectifiers, the Swiss rectifier employs a buck‐type topology, which significantly reduces the voltage stress on power devices. It achieves high power factor (PF) and low input current total harmonic distortion (THD) through a harmonic injection network. The rear‐stage interleaved three‐rail LLC resonant converter operates near its resonant frequency, leveraging soft‐switching techniques and a star‐connected topology to minimize switching losses and ensure balanced phase currents, achieving a peak efficiency of 97.5%, eliminating the need for rear‐stage control loops. The overall charger achieves a peak efficiency of 95.6% with excellent voltage regulation. This work establishes a high‐efficiency framework for AGV charging, which can cooperate with the wide range regulation of Swiss rectifier and the efficient isolated output of LLC‐DCX under a simplified front control scheme.