Resilient Wide-Area Damping Control to Mitigate Strong Cyber Attack: A Multiple-Controller Switching Approach

The growing risk of cyber attacks targeting wide-area damping control (WADC) has spawned much research on designing attack-resilient controllers recently. However, the issue of attack strength did not get enough attention so that most existing resilient WADCs may fail to defend strong attacks. To address this problem, this paper proposes a multiple-controller switching approach based resilient wide-area damping controller (MCS-RWADC) to suppress inter-area oscillations and mitigate strong attacks. It is inclusive of multiple secure networked prediction control based modules (SNPMs) and a switch-monitor module (MSM). The SNPM can detect attacks, differentiate attack strength and compensate for weak attacks. In terms of strong attacks, multiple SNPMs are implemented to work as backup and three operating states as well as the corresponding switching rules are designed to realize automatic switching among them. MSM is responsible for monitoring the states and directing the switching. Case studies are conducted on a 4-area 5-terminal voltage source converter-based multi-terminal high voltage direct current based offshore wind farm integration system. Simulation results verify MCS-RWADC cannot only suppress the inter-area oscillation but also handle the strong attacks under a wide range of operating conditions with various wind power output.