Reduced-Scale Wide Area Control System Design Based Upon the Dominancy Index Analysis

The objective of this paper is to develop an efficient wide area control (WAC) system with minimum possible involvement of system-wide entities. The wide area control signals are generated for generators’ excitation systems. The state feedback control technique is employed. In the conventional approach, the WAC system is realized by involving all the generators in the WAC loop. This may requires a large communication network infrastructure increasing both the cost and complexity of the WAC system. In contrast, the approach that is employed in this paper is based upon the identification of generators that are primarily responsible for causing the inter-area oscillations. Thus, instead of providing wide area control signals to all the generators, those are generated only for the dominant generators in inter-area oscillatory modes. Furthermore, only the states of dominant generators are considered for generating WAC signals. The H 2 -norm optimization technique with structural constraints is employed to get the required state feedback gain matrix. The effectiveness of the proposed WAC system is verified by considering different case studies through off-line simulations.