Design of a decentralized wide-area control system to tolerate the loss of communication paths based on coherency analysis

Abstract

The objective of this article is to design a wide-area control (WAC) system based on coherent groups of generators to overcome the loss of data and communication failures. In the conventional approach, the wide-area controller is designed by employing the state feedback control. It requires all the states on the controller input side and sending signals to all generators’ excitation systems on the output side. Therefore, good communication paths are necessary to get quality data every time. In addition, there should not be any data loss or false data due to phasor measurement units (PMUs) installed at every generator. However, it is not possible to get quality data without losing anything. Hence, it leads to the unstable condition of the entire power system. To address this problem, the area-wise coherency-based WAC system is proposed in this article to overcome the above-mentioned problems. The entire power system is divided into different areas based on coherency. Therefore, the centralized WAC system is divided into decentralized WAC systems based upon coherent groups of generators. This can be achieved by employing structurally constrained H2-norm optimization. Moreover, to validate the strength of the proposed controller, it is compared with different existing controllers reported in the literature by considering different case studies on IEEE-39 and IEEE-68 bus systems.