A Half-Bridge Single-Stage AC–DC Converter With Single- and Three-Phase Compatibility

This article presents a single-stage ac–dc converter based on a dual-active half-bridge topology, supporting both single- and three-phase operations. The proposed architecture employs three interleaved totem-pole legs on the ac side and three half-bridge legs with split capacitors on the dc side, reducing the switch count compared to the previous full-bridge approach. The converter achieves full zero-voltage switching (ZVS) for all switches in continuous conduction mode (CCM) and zero-current switching (ZCS) for dc-side switches in discontinuous conduction mode (DCM). For single-phase operation, an integrated split capacitor-type active power decoupling (APD) circuit eliminates the second-harmonic ripple in the dc charging current without additional components. To validate the concept, an 11-kW laboratory prototype was developed and tested under both single-phase (220 V_ac) and three-phase (380 V_ac) inputs, with battery voltages ranging from 400 to 800 V_dc. The experimental results demonstrate a peak efficiency of 96.85%, a grid current total harmonic distortion (THD) below 3%, and a power density of 2.7 kW/L.