During the process of energy storage clusters participating in power system Automatic Generation Control (AGC), the rational allocation of command power directly impacts the execution effectiveness of frequency regulation commands. Most existing strategies allocate power based on the proportional rated power, without considering the differences in capacity and power among diverse types of energy storage units. This can easily cause the State of Charge (SOC) of some energy storage stations to rapidly exceed limits, leading to output limitation, significant command tracking errors, and ultimately compromising system stability. To address the aforementioned issues, this paper proposes a frequency regulation control strategy for energy storage clusters based on SOC feedback. Firstly, considering the fundamental process of AGC, a cooperative control architecture for energy storage clusters participating in AGC regulation is designed. Subsequently, a reference value for the available capacity of the energy storage is formulated, and a regulatory objective for the energy storage cluster considering changes in available capacity is constructed. The power allocation scheme for each AGC command is determined with the goal of minimizing the deviation between the available capacity and its reference value. Finally, the power output distribution for the energy storage units is solved using the Lagrange multiplier method. Simulations analyzing both frequency regulation command tracking error control and the SOC control of energy storage stations verify that the proposed strategy ensures the effective execution of AGC commands.
Li et al. (Thu,) studied this question.