Analysis and optimal parameter selection of Full bridge bidirectional CLLC converter for EV

Resonant converters, especially the full-bridge bidirectional CLLC resonant converter, has obtained greatly attention due to its advantages of achieving high efficiency and high power density with operating at high frequency. However, the resonant tank is more complicated, which results in great impediments in optimally designing the resonant tank parameters. In this paper, an simplified design method of resonant tank based on fundamental harmonic approximation (FHA) is adopted. In detailed analysis and optimal resonant converter such as voltage gain characteristic, zero voltage switching (ZVS) restriction and device stress analysis. Finally, a 1.2 kW prototype is built, and the experimental results verified the proposed method.