基于分层优化的大容量混合储能系统能量管理策略

Energy Management Strategy of Large-scale Hybrid Energy Storage System Based on Layered Optimization

针对大容量混合储能系统（HESS）存在的多储能介质协调配合、多储能单元功率分配问题,提出一种＂储能系统-介质组-储能单元＂逐级优化的双层能量管理策略。中心分配层采用融合超级电容组荷电状态（SOC）的改进低通滤波算法,得到各介质组的功率指令。通过状态识别和人工干预,弥补该算法易导致介质组功率状态相反的不足,引入电池组功率爬升限值Plimit,进一步平滑电池组的功率输出。局部分配层引入储能系统持续可调度性和运行经济性的概念,分别建立电池组、超级电容组功率分配模型,完成上层功率指令在组内各储能单元之间的优化分配。以某储能电站某日13：00—13：30的实际出力为算例,利用AMPL/IPOPT求解器进行求解。结果表明,所提策略在满足电网对于储能系统功率需求的同时,能够合理分配各储能单元功率,使其SOC集中于0.4~0.8区间,保证各单元均留有足够的充、放电裕度,同时节约电池组运行费用17.7%。

In accordance with the coordination among different energy storage media and power allocation among parallel-connected energy storage units（ESUs） in the large-scale hybrid energy storage system（HESS）,a double-layer energy management strategy that distributes power step by step with the whole HESS,the medium packs,and the ESUs is proposed.The central distribution layer adopts the improved low-pass filtering algorithm with the state of charge（SOC） of ultracapacitor pack to obtain the power instructions of each pack.By means of state identification and artificial intervention,the algorithm＇s disadvantages that easily lead to opposite operation states between medium packs are solved.The introduction to the power limit of battery pack Plimit further smooths its output.Considering the sustainable scheduling and operation economy of the HESS,the power distribution models of battery units and ultracapacitor units are established,respectively,in the local distribution layer,and the power instructions from the upper layer are further distributed between various ESUs in each pack.Finally the output of an energy storage station at 13：00—13：30 in a day is used as an example to verify the effectiveness of the proposed strategy.The results show that this strategy can reasonably distribute power to every ESU（so that their SOCs remain in 0.4~0.8）,and save the operating cost of the battery pack about 17.7%.