面向电网二次调频需求的“PXP”储能集群分布式均衡控制策略

A Balancing Control Strategy for “Power-X-Power” Energy Storage Cluster in System Load Frequency Control

电力储能是维持新能源高渗透形势下电网频率稳定的有效手段,分散布置、统一调度是其参与系统二次调频的主要控制模式。针对现有控制策略分配二次调频需求合理性不足的问题,该文提出面向二次调频需求的PXP储能集群分布式均衡控制策略,其中PXP储能表示一类将电能(power)转化为其他形式能(X)再转回电能(power)的储能形式。该策略通过构建考虑储能实时容量的调频耗量函数,利用分布式算法,以调频耗量最小化为目标,实现对系统调频需求的最优分配。仿真结果表明,该策略能够打破功率型和能量型储能的界限,实现集群容量的均衡控制。同时,分布式算法使控制策略的运算速度显著提升,满足储能即插即用的要求。综上所述,该文所述策略通过对PXP储能集群在二次调频中的高效利用,提高了电网频率的稳定性。

With the high penetration of various renewable energy forms, energy storage systems(ESS) can effectively preserve the system’s frequency stability, while a distributed ESS can operate under a centralized control strategy in the system automatic generation control(AGC). In this work, we aimed to solve the improper frequency regulation demand allocation presented by current control strategies by suggesting a distributed balancing AGC strategy appropriate for PXP ESS clusters(an ESS type that converts power to other energy forms and then back to power). Specifically, the control strategy relied on a frequency regulation cost function that considers the real-time capacity of ESS, while the distributed nature of our algorithm optimally allocated the system frequency regulation demand aiming to minimize the frequency regulation cost. Our experimental results were highly appealing, demonstrating that the proposed control strategy could break the boundary between power-type and energy type ESS and realize the SoC balancing. Additionally, the distributed algorithm was highly computationally efficient, meeting the plug-and-play ESS requirements. In summary, the strategy in this paper realized the efficient use of PXP ESS cluster in AGC, and improved the frequency stability of the control area.