An EV On-Board Charger Based on Dual-Boost AC-DC Converter

This paper evaluates the performance of a double-stage converter for electric vehicles onboard charger applications. The dual-boost AC-DC converter is chosen as a front-end converter since it has higher efficiency, small passive element size, and lower EMI interference than the other AC-DC converters. A coupled inductor-based design for the AC-DC converter is chosen to overcome issues related to reserve current flowing problems for the rectifier body diodes and achieve zero-current switching (ZCS). Based on an LLC resonant network, the back-end converter provides galvanic isolation. To achieve ZVS, the LLC resonant converter frequency is higher than the resonance frequency. The suggested LLC resonant converter differs from the traditional LLC resonant in using two identical tiny transformers instead of utilizing one large transformer. This approach reduces the current stress on the secondary winding and decreases converter diode conduction losses.