A Two-stage Standard On-Board Electric Vehicle Charger with Minimum Switch Count

A novel two-stage standard battery charger with minimum switch count is presented in this paper for electric vehicle charging application. The first stage is responsible for AC to DC conversion with power factor correction operation that consists of two switches and two diodes. The second stage is a DC-DC converter having a half bridge LLC resonant circuit along with an isolation transformer. The complete charger consists of only four switches and four diodes, which is minimum among the reported literatures. It’s operation and control strategy are presented in this paper. A 470 W scaled down laboratory prototype is built to verify the proof of concept. The proposed charger is tested to charge a battery set of 24 V, 30 Ah using CC-CV logic with a maximum efficiency of 97.5%. The prototype is also tested with resistive load at its ratted power and dynamics results are captured. A TMS320F28335 DSP board is used to implement the control scheme.