Interleaved Boost Full-Bridge – LLC Resonant Converter with Optimized Turn Ratio for Electric Vehicle-to-Load Applications

This paper proposes a converter configuration for V2L (Vehicle-to-Load) applications in EVs consisting of two conversion stages (DC/DC and DC/AC) and focuses on optimizing the transformer turn ratio to improve the efficiency of the DC/DC converter stage for this application. The proposed DC/DC converter is combining from a two-phase interleaved Boost converter and a full-bridge LLC circuit together by virtue of sharing the same full-bridge switching unit. By combining the two converters, 4 switches are eliminated, reducing the volume by 15.5% and cost by 146$. Since the converter operates as a single-stage converter, efficiency can improve by 0.8% compared to conventional two-stage converter. Main system characteristics are presented, followed by the optimal design process for the turn ratio of the transformer in the converter with key parameters. Simulation results from Plecs software with input range of 260 − 460 V, output voltage of 400 V , fixed operated switching frequency of 100 kHz , and 2.4 kW are provided to validate the design process. Finally, a comparison of efficiency is made with conventional two-stage converter.