A Three-Phase Interleaved AC-DC Converter Based Electric-Vehicle Off-Board Battery Charger Station

Abstract

This paper presents a universal off-board charger for electrical vehicles (EVs), that can charge different categories of EVs, from light low-voltage EVs to heavy high-voltage EVs. The proposed off-board battery charger is based on an interleaved AC-DC converter such that each supply phase is connected to an interleaved buck-boost converter through an isolating transformer followed by a bridge rectifier. To ensure of stable operation of the proposed charger, the control strategy contains three flowed control loops. The outer loop is to regulate the charger output voltage. While the middle-cascaded loop is for battery charging current control, the last control loop is used to ensure that the grid current is sinusoidal at the unity power factor. The performance of the off-board battery charger and its capability to operate as a level ‘3’ charger with a wide voltage range is tested using PSCAD/EMTDC simulation software.