计及调频成本和荷电状态恢复的多储能系统调频功率双层优化

Two-layer Optimization of Frequency Modulation Power in Multi-battery Energy Storage System Considering Frequency Modulation Cost and Recovery of State of Charge

针对电网中不同类型储能电站调频成本、剩余调频能力存在差异、储能电站内部储能单元荷电状态(state of charge,SOC)过高或过低的问题,提出计及调频成本和SOC恢复的多储能系统调频功率双层优化策略,该策略包含调频功率优化层和SOC优化层:在调频功率优化层引入与储能电站剩余调频能力相关的抗拒系数,与调频成本共同构成目标函数,根据不同类型储能电站的调频成本和剩余调频能力实现调频功率优化分配;在SOC优化层引入SOC权重,以恢复储能单元SOC为目标对调频功率优化结果进行再分配。采用包含3种不同电池类型的区域电网验证所提分配策略的有效性,结果表明:与3种对比策略相比,所提策略不仅具有较好的经济性,还能恢复各储能单元的SOC,显著提高了调频效果。

Aiming at the problems in the power grid such as the difference in frequency modulation(FM)cost and residual FM capacity of different types of battery energy storage power stations(BESPSs),and the state of charge(SOC)of battery energy storage units(BESUs)in BESPSs could be too high or too low,a two-layer optimization strategy which takes FM cost and SOC recovery into account in multi-battery energy storage system was proposed.The strategy includes FM power optimization layer and SOC optimization layer.In the FM power optimization layer,the resistance coefficient related to the residual FM capacity of the BESPS was introduced.The objective function of this layer was composed of resistance coefficient and FM cost,so that the optimal distribution of FM power between different BESPSs can be realized according to the FM cost and residual frequency modulation capacity of different BESPSs.The SOC weight was introduced in the SOC optimization layer which can reallocate the FM power of different BESPSs to recover the SOC of BESUs.A regional power grid with three different battery types was used to verify the effectiveness of the proposed strategy.The results show that compared with the three contrast strategies,the proposed strategy not only has better economic benefits,but also can restore the SOC of BESUs and improve the FM effect of BESPSs.