Defense Strategy Against Load Redistribution Attacks on Power Systems Considering Insider Threats

In recent years, cybersecurity is emerging as one of the most critical problems to the normal operation of power systems. Meanwhile, insider threats are considered as a strategic and serious challenge in the cybersecurity research and have attracted increasing attention. In this article, the detailed model of load redistribution (LR) attacks against the power systems considering the presence of insider threats is developed. The LR attack problem is formulated with a security resource allocation game model. Information leakage of the system operator's defense strategy by the insider to the external attacker is considered in the proposed game model. The optimal strategies of both the system operator and attacker in the presence of the insider are calculated to maximize their own payoffs. In so doing, the impacts of the insider in the LR attacks can be investigated with the proposed security resource allocation game model. Case studies based on the IEEE 39-bus and IEEE 118-bus test systems were conducted to validate the proposed model. The results of the case studies show that the information leakage by the insider will increase the payoff of the attacker in the LR attacks. The damage on the grid can be considerable even if the information leakage probability is small. The proposed defense strategy is able to reduce the expected operation cost of the system under the LR attacks with the information leakage due to the insider threats.