Losing Control of your Network? Try Resilience Theory

TL;DR

This paper develops resilience conditions for cyber-physical networks facing actuator control failures, analyzing how local malfunctions can destabilize entire systems, with applications to microgrids and power systems.

Contribution

It introduces new resilience criteria for networks with control authority loss at a node, quantifying destabilization impacts and illustrating with practical examples.

Findings

Resilience conditions for networks with control loss are established.

Malfunctions at a single node can destabilize entire networks.

Applications demonstrated on microgrid and IEEE power system examples.

Abstract

Resilience of cyber-physical networks to unexpected 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 malfunctions and catastrophic cyber-attacks. Following such adverse events, we investigate scenarios where a node of a linear network 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, on an islanded microgrid, and on the linearized IEEE 39-bus system.