Identification and Prioritization of Critical Transmission Lines Under Malicious Physical Attacks

Transmission lines, as essential components for power transmission in the grid, are often exposed to complex external environments, making them vulnerable to malicious physical attacks and natural disasters. Therefore, identifying the criticality of transmission lines and ranking their importance is crucial for enhancing the grid’s resilience to such low-frequency but high-impact events. This paper proposes a method to evaluate the importance of transmission lines under malicious attack conditions. This approach is based on an analysis of the attacker’s available resources, the most effective attack strategies, and the system operator’s re-dispatch actions following an attack. A three-tiered optimization model is formulated to pinpoint the system’s most vulnerable transmission lines, with the goal of enhancing their resilience to both physical threats and natural calamities. Furthermore, given the unpredictability of the attacker’s behavior, a distributed robust optimization framework is introduced to identify these critical lines under uncertain attack scenarios. To quantify the importance of critical transmission lines in enhancing system resilience to malicious physical attacks, a metric for assessing their criticality is introduced. The effectiveness of the proposed method is validated through its application to the IEEE RTS-79 test system. The results demonstrate that the method effectively identifies and ranks critical transmission lines, improving the grid’s ability to withstand potential threats from malicious physical attacks.