Robust decentralised load-frequency control of multi-area power systems

A robust decentralised load-frequency controller, based on the Riccati-equation approach, is proposed for multi-area power systems with parametric uncertainties. It comprises N local robust load-frequency controllers for a N-area power system. N interlinked Riccati equations are produced initially which are separated via a decoupling technique. Bounds of system parametric uncertainties are included in these Riccati equations to improve the robustness of the intended controller. One local robust load-frequency relationship is obtained by solving the corresponding decoupled Riccati equation. It operates on its local measurements; feedback from other areas is not needed. The overall system is asymptotically stable, for all admissible system parametric uncertainties, when all the local load-frequency controllers are working together. Good performance is reported from the studied three-area power system even in the presence of the generation-rate constraint