串联液态金属电池组均衡控制策略研究

Study on strategy of balance control for liquid metal battery in series

液态金属电池是一类廉价高效、适合规模电能存储的新型储能电池技术。在分析液态金属电池特性的基础上,研究了一种基于开关矩阵的电感型均衡电路,提出以荷电状态(SOC)作为均衡变量,以SOC极大和极小的电池单体作为均衡对象,通过"变步长"方式对均衡电流进行控制的cell-to-cell均衡控制策略,并阐明了其具体的工作原理。利用Ma tla b/S imulink软件构建了串联液态金属电池组均衡控制系统模型,并针对串联液态金属电池组处于静置状态和恒流充电状态分别进行均衡控制仿真分析。该均衡控制策略适用于电池组的各种运行状态,可有效提高电池组中液态金属电池的一致性和容量利用率。

Liquid metal battery is a kind of new energy storage battery technology which is cheap and efficient and suitable for large-scale electric energy storage. On the basis of analyzing the characteristics of liquid metal battery,an inductance balance circuit based on the switch matrix was studied for the balance control of liquid metal battery in series. A cell-to-cell balance control strategy using SOC as the equilibrium variable, the maximum and minimum SOC batteries as the equilibrium objects were proposed to control the balance current by a variable-step-size method. Then, the specific working principle was illustrated. The Matlab/Simulink software was adopted to build an equilibrium-control-system model for liquid metal battery in series. Besides, simulation analyses were carried out according to the series liquid metal battery in a static and charging state, respectively. The balance control strategy was suitable for various operation states of the battery pack, and significantly improved the consistency and the capacity utilization for the pack of liquid metal battery.