Attack Intensity Dependent Adaptive Load Frequency Control of Interconnected Power Systems Under Malicious Traffic Attacks
Yajian Zhang, Chen Peng, Chuanliang Cheng, Yu‐Long Wang
Abstract
Malicious traffic attack can prolong the transmission delay of normal data flows by exhausting the limited bandwidth with injecting numerous invalid data packets. For the networked load frequency control (LFC) systems, the traffic attacks can cause the control performance deterioration or even instability. In this paper, an adaptive LFC scheme where the controller gains can be flexibly adjusted according to the attack intensities is proposed. Firstly, to quantitatively evaluate the impact of traffic attacks on the network transmission performance, the relationship between attack intensity and transmission delay bounds of normal data flows in multi-hop transmission process is well revealed based on deterministic network calculus. Secondly, to alleviate the adverse impacts of traffic attacks and improve the control performance under low-level attack intensities, the studied systems are described as a series of subsystems with the actual transmission delays of normal data flows as the switching decisions. Thirdly, a controller bank corresponding to all the attack intensities is elaborately constructed. The constraints and update criteria of each controller in the bank are strictly deduced in the switching control framework. Finally, the effectiveness of the proposed adaptive method is verified by four case studies.