WAM-signal-based decentralised fuzzy control for large power systems with unavailable states

Abstract

For the stability enhancement of large power systems, this study introduces a novel decentralised fuzzy control design method by using wide-area measurement (WAM) signals. First, a set of equivalent Takagi-Sugeno (T-S) fuzzy models are extended in order to accurately represent the non-linear dynamics of large power systems. Furthermore, taking consideration of systemic states not all available, a fuzzy observer is proposed to estimate these states. Then, a fuzzy-observer-based decentralised state feedback controller is designed. Based on Lyapunov functional approach and H ∞ control method, some sufficient conditions for the existence of the controller are cast into the feasible problem of LMIs, by which the system can be asymptotically stabilised. Moreover, the minimising approach is proposed to search the suboptimal upper bound value of H ∞ performance function. Finally, the better control performances of the proposed methods are shown by the simulation examples.