On resilience analysis and quantification for wide-area control of power systems

Wide-area control is an effective mean to reduce inter-area oscillations of the bulk power system. Its dependence on communication of remote measurement signals makes the closed-loop system vulnerable to cyber attacks. This paper develops a framework to analyze and quantify resilience of a given wide-area controller under disruptive attacks on certain communication links. Resilience of a given controller is measured in terms of closed-loop eigenvalues under the worst possible attack strategy. The computation of such a resilience metric is challenging especially for large-scale power systems due to the discrete nature of attack strategies. In this paper, we propose an optimization-based formulation and a convex relaxation approach to facilitate the computation. Furthermore, we develop an efficient algorithm for the relaxed problem with guaranteed convergence to identify structural vulnerabilities of the system. Simulations are performed on the IEEE 39-bus system to illustrate the proposed resilience analysis and computation framework.