Cyber-Physical Power System Layers: Classification, Characterization, and Interactions

TL;DR

This paper proposes a classification and characterization framework for the layers and interactions in cyber-physical power systems to improve modeling accuracy for reliability and failure analysis.

Contribution

It introduces a systematic method to classify system layers and characterize their interactions and intra-actions based on functions and components.

Findings

Layer classification based on shared functions.

Identification of inter-layer interactions and their impact.

Characterization of intra-actions within layers.

Abstract

This paper provides a strategy to identify layers and sub-layers of cyber-physical power systems (CPPS) and characterize their inter- and intra-actions. The physical layer usually consists of the power grid and protection devices whereas the cyber layer consists of communication, and computation and control components. Combining components of the cyber layer in one layer complicates the process of modeling intra-actions because each component has different failure modes. On the other hand, dividing the cyber layers into a large number of sub-layers may unnecessarily increase the number of system states and increase the computational burden. In this paper, we classify system layers based on their common, coupled, and shared functions. Also, interactions between the classified layers are identified, characterized, and clustered based on their impact on the system. Furthermore, based on the overall function of each layer and types of its components, intra-actions within layers are characterized. The strategies developed in this paper for comprehensive classification of system layers and characterization of their inter- and intra-actions contribute toward the goal of accurate and detailed modeling of state transition and failure and attack propagation in CPPS, which can be used for various reliability assessment studies.