Coordinated design of damping controllers for robustness of power systems stability

This paper considers the coordinated design of power system stabilizers and supplementary control of flexible AC transmission systems (FACTS) devices aiming at the robustness of the control scheme for drastic changes in the operating condition. The problem is treated as the design of a single state feedback controller for the whole power system. The existence of several controllers is taken into account by introducing structural constraints in the design. A design method that explicitly considers both the coordination and the robustness issues is presented. The method is based on the formulation and solution of an augmented Riccati equation. A benchmark illustrates the limitations of the classical control design and the robustness achieved by the proposed design method.