大功率动力电池组BMS的主动均衡混合策略

Active balancing hybrid strategy for BMS of high-power battery pack

由于电池的不一致性,电动汽车、叉车以及其他大功率动力电池组的电池管理系统(battery management system,BMS)至关重要,精确的荷电状态(state of charge,SOC)估计和高效的均衡策略是BMS的技术核心。基于同步双向反激式变压器的均衡电路拓扑,提出一种以电池SOC、电压为均衡变量的分段式主动均衡混合策略。通过搭建BMS电池组实验平台,开展了充放电阶段的均衡实验,结果显示充电阶段均衡后电池组总容量提升了2.3%,单电池电压极差由74 mV减小至9 mV;放电阶段均衡后单体SOC误差不大于0.5%。实验验证了所提主动均衡混合策略的有效性与可行性,能较好地改善电池组的不一致性。

Due to the inconsistency of batteries,the battery management system(BMS)of electric vehicles,forklifts and other high-power battery packs is extremely important.Accurate sate-of-charge(SOC)estimation and efficient balance strategy are the technical core of BMS.Based on the balance circuit topology of the synchronous two-way flyback transformer,this paper proposed a segmented active balanced hybrid strategy with battery SOC and voltage as the balanced variables.According to BMS platform,the balance experiment of battery pack charge and discharge phase was carried out.After the charge balanced,the results show that the total capacity increases by 2.3%and the cell voltage error range is reduced from 74 mV to 9 mV;the battery pack SOC error is not more than 0.5%after the balance of discharge phase.The effectiveness and feasibility of the proposed active balance hybrid strategy is verified by the experiments,which can effectively improve the inconsistency of the battery pack.