基于电感的锂电池组双向主动均衡控制研究

Research on bidirectional active equalization control of lithium battery pack based on inductance

针对锂离子电池组使用过程中各单体电池出现的能量不一致性问题,构建一种基于电感能量双向转移式的主动均衡拓扑结构,并依据OCV和SOC对应关系提出了相邻SOC差值和电压双变量的均衡控制策略。电感与锂电池之间通过主回路和次回路组合的模式实现单体电池间的能量转移,以Buck-Boost均衡电路为基础,调节PWM驱动信号占空比提高均衡速度和效率,并以UKF算法估计SOC,对各单体电池的SOC进行估计排序。锂电池充放电及静置仿真的结果表明,电池组之间SOC差值控制在3%以内,电压差值均衡在0.01 V以内,均衡速度相较于传统的电感均衡提高了51%。研究表明,该方法能够很好地完成电池组的能量均衡管理,效率相对较高,提高了电池的使用寿命。

Aiming at the energy inconsistency of each battery during the use of lithium-ion battery packs,an active balancing topology based on inductor energy bidirectional transfer was constructed,and a balancing control strategy of adjacent SOC difference and voltage bivariable was proposed according to the corresponding relationship between OCV and SOC.The energy transfer between the inductor and the lithium battery was realized by the combination of the main loop and the secondary loop mode.Based on the Buck-Boost equalization circuit,the PWM drive signal duty ratio was adjusted to improve the equalization speed and efficiency.The SOC was estimated by the UKF algorithm,and the SOC of each battery was estimated and sorted.The results of charge-discharge and static simulation of lithium battery showed that the SOC difference between battery packs was controlled within 3%,the voltage difference was equalized within 0.01 V,and the equalization speed was increased by 51%compared with the traditional inductance equalization.The results showed that this method could complete the energy balance management of the battery pack well,the efficiency was relatively high,and the service life of the battery was improved.