Robustness Assessment of Cyber-Physical Power Systems Considering Cyber Network Performance

The integration of cyber and physical networks in modern power system introduces complex interdependencies that necessitate effective robustness assessment frameworks. In this paper, we propose a novel robustness assessment method for cyber-physical power systems (CPPS), which integrates structural and functional robustness. Firstly, an interdependent dynamic hierarchical network model that accounts for static topological structure, functional attributes and dynamic operational characteristics of cyber-physical power system is established. Based on the model, a probabilistic cascading failure model considering topological connectivity loss, power flow overload, cyber functional failures, and cyber-physical dependence is proposed. The proposed model quantifies the cross-layer impact of cyber-layer impairments (such as communication delay and data loss) on physical-layer operation. Finally, the impacts of cyber network performance and initial failure modes on the robustness of the coupled system are analyzed. The results show that an excellent processing performance and topological connectivity of cyber network can enhance the robustness of the coupled system, and the failure of high-degree nodes is more likely to trigger more severe cascading failure results than the failure of high-betweenness nodes.