A Robust Strategy for Leveraging Soft Open Points to Mitigate Load Altering Attacks
Zhaoxi Liu, Lingfeng Wang
Abstract
Power system cybersecurity is emerging as a critical and urgent problem to the energy sector due to the ongoing power grid modernization initiative. Load altering attack (LAA) is an important category of cyberattacks on the modern power systems, in which the attackers may damage the grid by viciously altering the remotely controllable loads (RCL) that are not properly protected. In order to mitigate the impacts of LAAs on the distribution systems, the promising soft open point (SOP) technology is deployed in this study. A two-stage optimization framework is proposed for the optimal installation and operation of SOPs for defending the distribution systems against LAAs. A chance-constrained optimization model is developed to guarantee the confidence level of the proposed two-stage model of SOPs in mitigating the impacts of LAAs. Further, a Wasserstein metric based distributionally robust chance-constrained (DRCC) optimization method is developed to ensure the robustness of the proposed model against the ambiguity of the empirical probability distribution in practice. Case studies were performed on a 69-bus test system to validate the proposed method. The results of case studies show that the proposed framework is able to mitigate the impacts of LAAs on distribution systems with the installation of SOPs. By applying the DRCC optimization method, the proposed model manages to keep satisfactory confidence levels under the ambiguous probability distributions in the case studies.