Optimal Design of Voltage-Frequency Controllers for Microgrids

This paper presents a systematic control synthesis framework for an optimal voltage-based frequency control (VFC) in islanded/isolated microgrids. The problem of voltage-based frequency control is formulated as an optimal ${\mathcal{H}_\infty }$ controller synthesis for the linearized microgrid model. The validity of model-reduction steps in which the feeders are neglected is discussed, and various centralized/decentralized control architectures are investigated. Multiple simulation studies are performed in MATLAB/Simulink to test and compare the performances of the control architectures in a microgrid test system. Simulation results confirm the robustness of the VFC controller with respect to simplifications in the system model, and proposed system disturbances compared to a non-optimal VFC.