Coordinated attacks against power grids: Load redistribution attack coordinating with generator and line attacks

With the increasing terrorism and sabotage activities, the power grid is becoming more vulnerable to various kinds of cyber and physical attacks. The coordination between the attacks could bring disastrous impacts. In this paper, two typical attack coordination scenarios are studied: the coordination between load redistribution (LR) attack and generator attack; and the coordination between LR attack and line attack. They are formulated as bilevel optimization problems, where the attacker in the upper level aims to maximize the load curtailment while the defender in the lower level makes effort to reduce the load curtailment. The case studies conducted based on an IEEE 14-bus system indicate that when attacking the measurements and essential generation/transmission elements in a coordinated manner, the attacker could maximize the damage with the limited attack resource by disrupting the physical system and misleading the power dispatch simultaneously. This study can provide meaningful insights on how to prevent and mitigate such high-impact, low-frequency (HILF) coordinated attacks.