锂离子电池组分层主动均衡研究

目的针对实际装备中使用的串联锂离子电池组的不一致性问题,提出一种基于Buck-Boost电路和反激式变压器均衡电路的分层主动均衡构架。方法以荷电状态(SOC)作为均衡标准,制定均衡策略,建立锂离子电池二阶等效电路模型以及开路电压(OCV)特性曲线来进行参数辨识与SOC估计。实现电池组内相邻电池单体间的能量转移以及电池组间任意模组到整体的能量双向传递。最后在Matlab/Simulink中搭建均衡模型进行仿真验证。结果分层主动均衡构架相比传统单一相邻电池均衡构架具有更好的均衡结果,其均衡效果提升了43.04%,均衡时间缩短了24.4%,均衡效率提高了12.61%。结论该分层主动均衡构架充分发挥了两种主动均衡的优点,改善了电池组的不一致性问题,并提高了整个电池组的充放电容量。

Study on the Hierarchical Active Equilibrium for Lithium-ion Batteries

Aiming at the inconsistency problem in series lithium-ion battery packs in actual equipment, a hierarchical active balancing architecture was proposed based on Buck-Boost circuit and flyback transformer equalization circuit. In this paper, the SOC was used as the equilibrium standard to formulate the equilibrium strategy. The second-order equivalent circuit model of the lithium-ion battery and the open circuit voltage (OCV) characteristic curve were established for parameter identification and SOC estimation. The energy transfer between adjacent battery cells in the battery pack and the energy transfer from any module to the whole battery pack were realized. Finally, the equilibrium model is built in Matlab/Simulink for simulation verification. The simulation results show that the hierarchical active balancing architecture has better balance results than traditional single adjacent battery balancing architecture. Its balancing effect has increased by 43.04%, balancing time has been shortened by 24.4%, and balancing efficiency has increased by 12.61%. The hierarchical active balancing architecture gave full play to the advantages of the two active balancing methods, improved the inconsistency of the battery pack and increased the charge and discharge capacity of the entire battery pack.