New three-phase on-board battery charger without electrolytic capacitor for PHEV application

This paper describes a three-phase two-stage on-board charger for a plug-in hybrid electric vehicle (PHEV). The proposed charger is composed of three identical single-phase modules connected in parallel. Each module has a cascaded structure composed of a high frequency resonant converter with constant switching frequency and a buck-boost converter in discontinuous conduction mode (DCM). The proposed on-board charger requires a small-rating DC capacitor so that large-capacity electrolytic capacitor can be removed. It has relatively low voltage stress in components due to DCM operation.