针对储能系统中电池组充放电过程中能量利用率以及系统运行安全性较低的问题,提出考虑SOC一致性的电池组双层动态均衡方法.首先,采用耦合电感与Flyback变换器搭建均衡系统双层架构,建立电池组端电压、均衡电流及占空比间的关联特性.为提高电池组的供能可靠性,系统引入故障切除功能,通过改变开关阵列导通状态实现故障电池组的快速切除;其次,考虑增补电池组剩余容量较大问题,利用传统最值法改进的双层极值法,以荷电状态(stage of charge,SOC)作为均衡目标变量,对增补电池组进行快速放电均衡;最后,设计充放电及静置均衡实验,对比传统最值法,分析常态及故障切除后电路的均衡速度与均衡效率.结果表明,提出的双层均衡方法可以将均衡速度提升约10%,且故障切除后电路的均衡效率最高可达95%以上.
A Two-layer Dynamic Equalization Method for Battery Modules Based on State of Charge
Aiming at the problem of low energy utilization and system operation safety during the charging and dis-charging process of battery modules in energy storage systems,we proposed a two-layer dynamic equalization method for battery modules based on state of charge.Firstly,the coupled inductor and Flyback converter were used to build the two-layer structure of the equalization system,and the correlation characteristics among the terminal voltage,equalization current and duty cycle of the battery pack were established.In order to improve the reliable energy supply of battery modules,the system introduces the fault removal function,which realizes the rapid removal of the faulty battery module by changing the on-state of the switching array.Secondly,the large residual capacity of the supplementary battery module was taken into consideration,and the two-layer extreme value method improved by the traditional maximum value meth-od was used to realize the rapid discharge equalization of the supplementary battery pack with the stage of charge(SOC)as the equalization target variable.Finally,charging,discharging and static equalization experiments were designed to compare the traditional most value method and analyze the equalization speed and efficiency of the circuit after normal and fault removal.The results show that the two-layer equalization method proposed in this paper can be adopted to in-crease the equalization speed by about 10%,and the equalization efficiency of the circuit after fault removal can be up to more than 95% .
battery modulesstate of chargecoupling inductancefault removaltwo-layer equalizationsecurity
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维普
