An Innovative Control Strategy for Fast Frequency Response in Battery Energy Storage Systems

This study addresses the challenge of low system inertia caused by the increased integration of renewable energy sources (RESs) into the power system. The primary objective is to minimize the energy consumption of fast frequency response (FFR) from battery energy storage systems (BESSs) while maintaining system stability and resiliency. To achieve this goal, the study proposes a system condition evaluation method based on the critical rate of change of frequency (RoCoF), which is derived from a streamlined nonlinear primary frequency control (PFC) model. By leveraging critical RoCoF, the proposed controllers are designed to ensure system stability with minimal FFR energy consumption. The proposed controller employs an adaptive reference for RoCoF control, resulting in reduced sensitivity to the control gain while achieving outcomes comparable to a RoCoF controller with a fixed reference and optimal gain. Simulations conducted on a modified IEEE 9-bus power system validate the controller's effectiveness in preserving system stability with lower sensitivity to control gain.