An Investigation of Coordinated Attack on Load Frequency Control

In this paper, optimal attack schemes against load frequency control (LFC) are studied by considering coordinated attack. By attacking sensor measurement (load) simultaneously, the attacker disrupts the normal operation of LFC, thus causing excess system frequency/generation excursions. From the perspective of the attacker, LFC system information availability is essential to the attack scheme design. In this paper, two scenarios, where LFC system information is and is not available to the attacker, are considered and optimal attack schemes are studied for these two scenarios, respectively. The optimal attack scheme design is modeled by an optimization problem with different objectives (attack goals): 1) maximization of frequency/generation disruption and 2) least-effort attack (minimization of attack cost). In consideration of counterattack, a threshold-based detection method is used to detect the optimal attack schemes. Two case studies, corresponding to these two scenarios, are simulated, and the results show that attack performances vary with different attack goals and the detection approach can screen out the compromised signals.