PNNL

Abstract

Resilience of cyber-physical networks to un- expected failures is a critical need widely recognized across domains. For instance, power grids, telecommunication networks, transportation infrastructures and water treatment systems have all been subject to disruptive mal- functions and catastrophic cyber-attacks. Following such adverse events, we investigate scenarios where a network node suffers a loss of control authority over some of its actuators. These actuators are not following the controller’s commands and are instead producing undesirable outputs. The repercussions of such a loss of control can propagate and destabilize the whole network despite the malfunction occurring at a single node. To assess system vulnerability, we establish resilience conditions for networks with a subsystem enduring a loss of control authority over some of its actuators. Furthermore, we quantify the destabilizing impact on the overall network when such a malfunction perturbs a nonresilient subsystem. We illustrate our resilience conditions on two academic examples and on the classical IEEE 39-bus system.