Cyber-Physical Modeling and Vulnerability Assessment of Substations for Transmission System Operator

• Published in: Electric power systems research Vol. 235; p. 110769
• Main Authors: S., Shashank, Gurrala, Gurunath, Sastry, P.S., Katewa, Vaibhav
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-10-2024
• Subjects: Bus-branch model; Common information model; Cyber–physical energy systems; Node-breaker model; Substation configuration; Vulnerability assessment; Substation configuration; Node-breaker model; Bus-branch model; Common information model; Cyber–physical energy systems; Vulnerability assessment
• ISSN: 0378-7796; 1873-2046
• DOI: 10.1016/j.epsr.2024.110769

In bulk power systems, the majority of interaction between cyber and physical components takes place in substations. However, in most of the cyber–physical power system models the physical layer is typically done using the bus-branch (BB) model, where each substation is considered as a single node. This approach will not capture the details of the cyber layer. This paper proposes a framework to model the substations using node-breaker (NB) models for physical system representation so that the detailed station configurations, the current and the voltage transformer positions, arrangements of protective relays, bay control units and associated communication infrastructure within the substations and its dependencies on the physical elements can be captured effectively using a single cyber–physical graph. Keeping a transmission system operator in view, who does not use power flow and security assessment tools for station operations and maintenance, a vulnerability assessment approach is proposed to assess the risk using some representative attack scenarios. The proposed approach is demonstrated using WECC 3-machine system for breaker and half station configuration. The attack scenarios are developed based on the real substation configuration and the adversary’s ability to understand the substation protection and BI/BO operations.
•A framework to model detailed substation configurations as a cyber–physical graph.•Impact factors are proposed for assessing the consequence of cyber attack for TSOs.•Two attack models are discussed considering adversary’s knowledge on the protection.•Proposed framework is implemented on WECC 3-machine system and results are presented.•Importance of securing IED placement info and of programmable BI/BO are highlighted.