锂离子电池纯电感分层均衡电路仿真研究

Simulation Study on a Pure Inductor-Based Hierarchical Equalization Circuit for Lithium-Ion Batteries

摘要: 为改善锂离子电池组在成组应用过程中因单体差异引起的一致性下降问题，对一种纯电感分层均衡电路进行了建模与仿真研究。该电路采用分层结构，以内层电感实现子组内部单体间能量转移，以外层电感实现不同子组之间的能量交换。在MATLAB/Simulink平台中搭建4节串联锂离子电池均衡模型，直接设定各电池模块初始SOC，并以SOC状态量作为均衡控制依据，对电路工作过程、SOC变化规律以及内外层电感电流特性进行了分析。结果表明，在设定参数条件下，纯电感分层均衡电路能够有效缩小电池组内单体SOC差异，均衡过程中内层与外层电感均可完成较稳定的储能与放能过程。研究结果验证了纯电感分层均衡电路的可行性，可为电感型均衡拓扑的参数设计与控制策略分析提供方向。

Abstract: To address the consistency degradation of lithium-ion battery packs caused by cell-to-cell differences during pack application, a pure inductor-based hierarchical equalization circuit was modeled and simulated in this study. The circuit adopts a hierarchical structure, in which the inner-layer inductors are used to transfer energy among cells within each subgroup, while the outer-layer inductor is employed to exchange energy between different subgroups. A four-cell series-connected lithium-ion battery equalization model was established on the MATLAB/Simulink platform. The initial state of charge (SOC) of each battery module was directly set, and the SOC variable was used as the equalization control criterion. The operating process of the circuit, the variation pattern of SOC, and the current characteristics of the inner- and outer-layer inductors were analyzed. The results show that, under the specified parameter conditions, the pure inductor-based hierarchical equalization circuit can effectively reduce the SOC differences among cells in the battery pack. During the equalization process, both the inner- and outer-layer inductors can achieve relatively stable energy storage and release, indicating that this method has good feasibility for battery equalization. The research results can provide a reference for the design and simulation analysis of active equalization circuits for lithium-ion batteries.