A transformer-based active balancing circuit with multiple energy transmission paths

Battery balancing technology is of great significance to ensure safe operation and maximize capacity utilization. This paper presents a novel direct balancing topology based on a transformer converter with multiple paths. According to different working conditions, the proposed topology can operate in different cases to achieve any-cell(s)-to-any-cell(s) direct equalization with fast speed and high efficiency. To further analyze the performance of the topology, the equivalent model is established and a series of theoretical analyses are conducted. Moreover, two different control strategies with k-means clustering and fuzzy control are developed for comparison. To verify the effectiveness of the proposed method, simulations, and experiments are carried out based on a four-series battery pack. Results show that the proposed approach can achieve good performance of equalization in terms of balancing speed, efficiency, and system flexibility. •A novel direct balancing topology based on a transformer converter with multiple paths is developed•Two different control strategies with k-means and fuzzy control are analyzed and compared•The proposed method achieves direct equalization in various cases with fast balancing speed and high efficiency.