Research on Hierarchical Equalization of Lithium Battery Packs Based on Bidirectional Cuk Converter

To address the issues of low balancing efficiency and long balancing time in traditional lithium battery pack equalization circuits, this study proposes a novel equalization topology using battery terminal voltage as the balancing variable. This structure employs multiple bidirectional Cuk converters working in coordination to establish a multi-path, small-scale energy transfer mechanism between battery modules and individual cells, optimizing the transmission path to accelerate the balancing process. To validate the effectiveness of the proposed solution, a simulation model was developed on the MATLAB/Simulink platform and evaluated in a test system consisting of four lithium batteries. The simulation results demonstrate that, by optimizing energy transfer paths and control strategies, the improved equalization circuit significantly reduces balancing time compared to traditional structures.