Optimal Active Cell Balancing for Lithium-Ion Battery Packs: A Two-Stage Strategy to Minimize Losses and Balancing Duration

This paper presents a novel two-stage optimization strategy to improve efficiency in active cell balancing for high-voltage lithium-ion battery packs. The proposed method utilizes a linear programming formulation, the Transportation Problem, to optimize charge redistribution, thereby minimizing conduction losses and balancing duration. Additionally, principles from Graph Theory, particularly Eulerian Paths, are used to reduce switching losses. In contrast to conventional rule-based controllers, the proposed algorithm achieves faster balancing, fewer switching events, and improved efficiency. The results demonstrate considerable improvements in balancing performance, reducing inefficiencies typically associated with high-voltage battery packs.