Battery Hierarchical Balancing Method Based on Series-Parallel Reconfigurable Topology

Inconsistencies within a battery pack will reduce its service life, and failure of a single battery within the pack will cause serious safety issues. In order to settle the matter, this paper proposes a series-parallel reconfigurable battery balancing topology and designs a balancing control strategy. Firstly, the operating principle of the offered balancing topology to change the series-parallel state of battery cells to complete balancing is introduced, and the fault removal method in the case of battery cell failure is given. Secondly, the battery state of charge is selected as the balancing variable and an easily expandable hierarchical balancing control strategy is designed. Finally, a simulation model is built in Simulink, and simulation experiments are carried out on the presented balancing method. The results demonstrate that the balancing topology given in this paper is 33.2% faster than the traditional balancing method. The experimental results also prove the necessity and effectiveness of the hierarchical balancing strategy.