Analyzing Cyber-Physical Modularity and Interdependence Using Bio-Inspired Graph Modeling

Modern power grids and other complex systems are a fusion of physical and cyber components, giving rise to intricate interdependencies. These interdependencies, however, also expose vulnerabilities that can be exploited by adversaries. This paper delves into the critical examination of these interconnections, inspired by Ecological Network Analysis (ENA). By drawing from ecological modeling, we aim to understand the role of cyber-physical interdependencies in the resilience of complex systems. We introduce various modeling methods, including bipartite and tripartite networks, to analyze and map these interdependencies in the context of the IEEE WSCC 9-bus and the ACTIV 200-bus case study. The paper explores how these models can identify key actors and assess network resilience. Through a detailed methodology, we apply ecological metrics and community identification techniques to comprehensively evaluate the system's interactions. The findings offer insights into the interplay of cyber and physical elements in power grids and other complex systems. These analysis methods show that tripartite networks produce more information on indirect interactions within a complex network. Additionally, they provide detailed information on how disturbances could propagate in a cyber-physical power system. Denial of service scenarios for the WSCC 9-bus and the ACTIV 200-bus case studies are employed to support this conclusion.