Robust Defense against Load Redistribution Attacks in Power Grids based on Reactance Control

Load redistribution (LR) attacks are covert, damaging, and able to achieve various attack objectives. Effective defensive measures are required to reduce the impact of LR attacks on power grids. Existing moving target defense (MTD) methods have been studied for attack detection based on transmission line reactance perturbation, but require sufficient deployment of distributed flexible AC transmission system (D-FACTS) devices to ensure the detection performance. However, large-scale D-FACTS device deployments are costly, which limit the efficiency of MTD methods in practical operations. As such, this paper coordinates the reactance control of a single transmission line with the generation dispatch to defend the power grid against LR attacks. Specifically, a reactance-control-based robust dispatch model is presented, which guarantees the system security as well as the economic performance without changing the reactance of a large number of transmission lines. A two-stage methodology utilizing the pattern search algorithm and column constraint generation (C&CG) algorithm is proposed to solve the dispatch model in an iterative process. Case studies based on the IEEE 14- and 118-bus systems verify the effectiveness of the proposed method in breaking through the security limits of the existing power grid and improving the economics of the robust defense.