基于模糊控制的锂离子电池组两级均衡方法

Two-level equalization method for lithium-ion battery pack based on fuzzy control

针对锂电池组在充放电过程中出现能量不一致的问题,本文提出了两级均衡拓扑,分为组内和组外。电池组内采用基于电感的环式结构均衡电路,实现了在相邻单体电池及首尾电池之间的能量双向环式转移新型主动均衡。电池组外采用基于单电感的集中式均衡拓扑,可以实现组间任意电池组之间的均衡。在均衡控制策略方面,以电池荷电状态为均衡变量,设计了模糊逻辑控制算法动态调整均衡电流,以减少均衡时间和提升均衡效率。使用MATLAB/Simulink软件进行模型搭建并仿真,实验结果表明,本文提出的能量传递拓扑比传统Buck-Boost电路在相邻单体间能量传递的拓扑要减少了24.46%的均衡时间。此外,与模糊逻辑控制算法相比,使用模糊逻辑控制算法在静置和充放电条件下,均衡后单体电池的标准差下降了约11%。验证了该均衡方案的可行性。

Aiming at the problem of energy inconsistency during the charging and discharging process of lithium battery packs,this paper proposes a two-level equilibrium topology,which is divided into inner and outer groups.The inductance-based ring structure equalization circuit is used in the battery pack,which realizes a new type of active equalization of bidirectional ring transfer of energy between adjacent single cells and the head and tail cells.A centralized balance topology based on a single inductor is used outside the battery pack,which can achieve balance between any battery packs between the packs.In terms of balancing control strategy,taking the battery state of charge as the balancing variable,a fuzzy logic control algorithm is designed to dynamically adjust the balancing current to reduce the balancing time and improve the balancing efficiency.Using MATLAB/Simulink software to build and simulate the model,the experimental results show that the energy transfer topology proposed in this paper reduces the equalization time by 24.46%compared with the traditional Buck-Boost circuit energy transfer topology between adjacent cells.In addition,compared with the fuzzy logic control algorithm using the fuzzy logic control algorithm under static and charge-discharge conditions,the standard deviation of single cells after equalization decreased by about 11%.The feasibility of the equalization scheme is verified.