Internal module equalization steps.

To maximize the driving range of electric vehicles, battery imbalance is the primary factor that hinders the full utilization of battery pack capacity. This article is based on a four-switch reconfigurable topology, which can flexibly connect, bypass, and parallel any battery cell within the module, and can maintain low voltage fluctuations without the need for a DC-DC converter. Based on this topology, a hierarchical equilibrium strategy combining inter-module K-means clustering analysis and intra-module splitting and recombination is proposed. This strategy can achieve full cell balance, thereby ensuring the maximum capacity utilization of the battery pack. The topology structure composed of 8 batteries was validated, and the experimental results confirmed that the proposed hierarchical balancing strategy supported by the reconfigurable topology increased the capacity utilization of the battery pack by 15.93%, and the maximum fluctuation rate of the battery pack terminal voltage was 0.9%.