A Bidirectional CLLC Resonant Converter for EV Battery Charger Applications

EVs have gained significant attention due to their independence from fossil fuels, as well as their ability to reduce greenhouse gas emissions. In this paper, a bidirectional CLLC resonant converter for EV charger applications is proposed, in which the voltage stresses of its power switches are reduced to half of its input voltage while it can transfer high power values. A detailed analysis of the converter operating principle and characteristics are provided in this paper. Several factors contribute to achieving high efficiency by using the proposed resonant converter, including zero-voltage switching (ZVS) on its primary side and zero-current switching (ZCS) on its secondary side, in both forward and reversed operation modes. An asymmetric CLLC configuration is used, which has one less inductance than the well-known symmetrical CLLC topology; hence, it is more compact and convenient for design and control, but its features are almost similar to the conventional symmetric bidirectional CLLC converter ones. Performance of the proposed converter has been verified through simulations conducted in PSpice/OrCAD.