Robust hierarchical damping controller for uncertain wide‐area power systems

Abstract

This study develops a new robust hierarchical predictive sliding mode controller to damp the wide-area electromechanical oscillations in an uncertain wide-area power system. The coefficient matrices of wide-area systems are often sparse matrices which cause the inverse calculation of them very complex or impossible. In the suggested approach, first the entire system is divided into several small subsystems with non-sparse matrices and lower order; then a new predictive sliding mode controller with robust reaching law is designed to provide the optimal performance and robustness to uncertainties and external disturbances. Also, the gradient of interaction errors is employed for coordination of overall wide-area system. The capability and efficiency of the developed control framework is verified through numerical simulations on an uncertain power grid with interconnected multi-areas, for various cases of perturbations and parameters’ uncertainties. Simulation studies illustrate the effectiveness of the suggested method to improve the wide-area power grid damping in terms of acceptable robustness to external disturbances and system's parameter variations, in comparison with two other methods which are adopted from the literature.