储能电池与常规机组配合参与一次调频的自适应控制策略

The adaptive control strategy of energy storage battery cooperating with conventional generating units to participate in primary frequency regulation

为充分发挥电池储能系统与常规机组在一次调频中的各自优势,文中对储能采用下垂控制与虚拟惯性控制结合的控制策略,通过设置随频率偏差变化而调整的下垂系数,实现增发功率在常规机组与储能之间的合理分配;为避免储能电池发生过充过放现象,提出一种考虑SOC反馈调整出力的自适应控制策略;电网中储能容量配置不如常规机组,设计一种储能适时投入与退出调频的控制策略,使储能在频率急剧变化或偏移至常规机组一次调频能力范围外时投入调频;在频率基本稳定时储能平稳退出调频以保持SOC。利用Digsilent/Power Factory软件对区域电网分别进行阶跃负荷扰动和连续负荷扰动仿真实验,结果表明在阶跃扰动下该控制策略可显著改善暂态频率特性,在连续扰动下可以兼顾频率偏移指标与SOC的保持。

In order to give full play to the advantages of battery energy storage system and conventional units in primary frequency regulation,the control strategy of combining droop control and virtual inertia control is adopted for energy storage.The reasonable distribution of additional power between conventional units and energy is realized by setting the droop coefficient adjusted with the variation of frequency deviation.In order to avoid the phenomenon of overcharge and over-discharge of energy storage battery,an adaptive control strategy is proposed which considers the output of SOC feedback adjustment.The configuration of energy storage capacity in the power grid is not as good as that of conventional units.A control strategy is designed to timely input and exit the frequency of energy storage,so that the energy storage can be put into the frequency when the frequency changes sharply or the energy storage is out of the primary frequency range of conventional units.When the frequency is basically stable,the energy storage exits the FM steadily to maintain the SOC.Finally,Digsilent/Power Factory software is utilized to simulate step load disturbance and continuous load disturbance of the regional power grid respectively.The results show that the control strategy can significantly improve the transient frequency characteristics under the step disturbance,and the frequency offset index and SOC can be maintained under the continuous disturbance.