An Investigation into Ecological Network Analysis for Cyber-Physical Power Systems

Abstract

Power systems consist of interdependent cyber and physical networks: the physical network supplies energy to the cyber network for data exchange, while the data exchange provides for observation and operation of the power system. This mix of a physical and a cyber/information network means that network disturbances can be synthesized in both physical and cyber forms. Cyber incidents in particular have been increasing, highlighting the importance of both designing for and measuring the reliability and robustness of cyber networks. Industry guidelines exist to inform network designs for security and availability, but they are limited when it comes to being able to rigorously account for cyber-physical interdependencies in these networks. This presents cyber-physical network designers with a lack of design tools to guide network creation. This paper introduces a bio-inspired approach that has been successfully applied to the physical component of power networks, extending it for evaluation and guidance in a cyber-physical power system. The power system's cyber-physical network is modeled here as an ecological food web. The potential benefits of selected ecological metrics related to food web resilience are evaluated, including robustness $(R_{ECO})$, average mutual information (AMI), cyclicity $(\lambda_{max})$ and cycling index (CI). The paper investigates the use of these metrics and our understanding of food web characteristics to enhance the resilience and robustness of cyber-physical network design and data routing. Two cases are explored to highlight this potential, a 3-substation and an 8-substation cyber-physical system. The analysis suggests that increasing redundancy in the network design and more equally distributing data flow can improve the security and availability of data being transferred to operators.