Invariant-set design of observer-based robust control for power systems under stochastic topology and parameters changes

Abstract

Power systems are subject to stochastic fluctuations which can be classified as topological or parametric. This paper models the random topological changes due to a series of lightning strokes hitting a transmission line (associated with open/reclose of circuit breakers) in a power system as a Markov jump system. Whereas the line reactance (depending on the phase conductors spacing) changes due to the random wind speed fluctuations, are represented as a stochastic external disturbances. A novel excitation control for a stochastic power system is developed. The optimal two-controller and observer gains are designed based on the attracting ellipsoid method and the linear matrix inequalities (LMI) optimization. The effectiveness of the proposed control is tested on a multimachine system.