Design and Verification of Active Balancing Circuit for Battery Management System Based on a Bidirectional Converter

This paper presents a modular design and validation for a battery management system (BMS) based on a dual-concentration architecture. The proposed architecture improves the BMS’s performance, such as the balancing process and a reduction in the number of components required by the BMS, including power switches, switching arrays, and energy storage elements. Generally, even an active balancing process still causes some energy loss, so this study applies a modified flyback converter with an active clamp for the battery module balancing process, which has a higher conversion efficiency, especially in low-power conditions. The simulation results of the balancing circuit are consistent with the measured results. To quantify the improvement of the balancing strategies on the balancing results, this study also presents four balancing strategies for the proposed BMS, wherein the balancing duration and maximum voltage error of the balancing strategy can be reduced by approximately 34% and 73%, respectively, compared with the worst-case scenario in the four balancing strategies.