孤岛微网中分布式储能SOC和效率均衡控制策略

Balancing control strategy of SOC and efficiency for distributed energy storage in islanded microgrid

在微网的运行中,不同储能电池的特性和初始状态不一致,会降低电池组间的功率分配精度。针对这一问题,提出了一种基于并联储能单元荷电状态(SOC)和充放电效率的储能均衡控制策略,以均衡电池差异和减少系统有功损失。所提方法采用分布式控制方式,将各分布式储能单元的SOC和充放电效率作为控制输入量,实时调整其输出功率,在满足系统功率需求的同时实现功率均分及并联储能单元间SOC和效率差异均衡。在此基础上,基于各储能单元SOC设计了均衡影响因子,采用两段法优化并联储能单元间SOC的均衡效果。通过MATLAB/Simulink仿真分析了所提控制策略在分布式负载变化、系统电源故障切除及有无均衡影响因子动态变化情况下的SOC均衡效果,仿真结果验证了所提方法的有效性和"即插即用"特性。

In the operation of microgrid, different types of battery energy storage systems have different characteristics and initial states, which will decrease the power allocation accuracy among battery packs. Aiming at this problem, a balancing control strategy of energy storage based on the SOC （ State Of Charge） and charging/discharging efficiency of parallel energy storage units is proposed to balance the difference of batteries and reduce system active loss. The proposed method adopts the distributed control strategy, the SOC and charging/discharging efficiency of each distri- buted energy storage unit are employed in the controller to adjust its output power in real-time ,thus realizing the equal power dispatch and implementing SOC and efficiency error balancing of parallel distributed energy storages. Based on this, the balancing factor is designed based on the SOC of each energy storage unit and the SOC balancing effect of parallel distributed energy storage is optimized by two-step method. The SOC balancing effects of the proposed control strategy are analyzed with MATLAB/Simulink in the conditions of distributed load changing, system power failure removing and whether the balancing factor changing dynamically. Simulative results verify the effectiveness and plug ＆ play characteristic of the proposed method.