Physical Security Threat Assessment and Resource Investment Allocation for Electric Power Substations

Ensuring the physical security of electric power substations is crucial for maintaining a reliable supply of electricity. The increasing prevalence of physical threats, such as physical attacks, vandalism, sabotage, etc., on electric power substations worldwide has resulted in widespread power outages. To enhance physical security in light of these high-impact, low-probability events, this paper proposes a physical security threat assessment approach to evaluate and enhance substation security against physical attacks utilizing the Substation Criticality Index (SCI) and the Threat–Vulnerability–Consequences Index (TVCI) on risk-based security-constrained economic dispatch. The primary objective is to provide power utilities with actionable insights to proactively strengthen their defenses within budgetary constraints by considering the criticality level of each substation. By incorporating social, economic, and electrical factors, this study simulated a physical attack (specifically a bus-isolating attack), on an IEEE 39-bus test system, and evaluated the resultant consequences and load loss. Upon computation of the SCI, substations are ordered according to their criticality, and computing the TVCI gives the risk of each substation which is used to obtain an optimized physical security investment based on substation vulnerability and the consequences of attacks. Thus, based on these results, decisions for prioritizing substation physical security and investments for hardening physical security are made. Furthermore, the experimentation showed that with the physical security investment, the overall TVCI score has significantly decreased with certain budgetary constant.