Fuzzy-observer-based robust tracking control for large interconnected power systems using WAMS

Technological advancement in the area of wide-area measurement systems (WAMS) has enabled the use of a combination of measured signals from remote location for robust control purpose. In this study, the robust tracking control problem of large power systems is studied by using WAM signals. First, for the purpose of accurate description of system dynamics, a Takagi-Sugeno (T-S) fuzzy model is employed to represent the large power system. Furthermore, taking consideration of states of the system not all available, a fuzzy observer is proposed to estimate these states. Consequently, a fuzzy-observer-based state feedback decentralized H∞ fuzzy control scheme is designed to solve the robust control problem for large power systems while taking into account complement of WAM signals. The design problem is parameterized in the form of a linear matrix inequality (LMI) problem which can be solved very efficiently using the convex optimization techniques. Finally, the better robust control performance of the proposed methods is verified by the simulation examples.