Design of H2-optimal structured state feedback controller for energy storage systems in power system frequency regulation

In this paper, an approach is proposed to design an H₂-optimal structured state feedback controller for energy storage systems (ESSs) participating in power system frequency regulation. The controller has a fixed structure that only requires a few measurable state variables as input, and makes a tunable compromise between control performance and capacity limits of ESSs. An augmented Lagrangian method is employed to calculate the optimal structured feedback gain under H₂ performance index. The proposed approach is simulated on a test system with two interconnected areas and an ESS. The simulation results show the control of the ESS contributes to suppress the frequency fluctuation, and there is a clear linkage between the assigned weights of controlled variables and the resulting changes in controller behavior.