Soft Open Points-Assisted Resilience Enhancement of Power Distribution Networks Against Cyber Risks

Cyberattacks are increasingly threatening the normal operation of electric power grids. The purpose of this study is to develop an optimization model for planning and operation of distribution systems to enhance the resilience to cyberattacks. A new distribution system planning method is presented utilizing a Defender-Attacker-Defender (DAD) tri-level model to improve the system resilience to withstand potential disruptions from cyberattacks. In the first level of the model, the system planner optimizes the Soft Open Points (SOPs) installation in the planning stage. The attacker’s objective in the second level of the model is to change the status of the network circuit breakers and jam the communication maximizing disruption of the system. The optimization of Distribution Generators’ (DGs’) outputs, SOPs’ power flow, and topology reconfiguration are comprehensively considered in the third level. The novel model presented in this paper considers hardening measures of the SOPs in response to the attacks on distribution systems. The Column and Constraint Generation (C&CG) algorithm is utilized to solve the proposed DAD model. A procedure is devised to solve the two-layer subproblem (the Attacker-Defender model), with the bottom layer being a Mixed Integer Second Order Cone Programming (MISOCP) problem. Finally, the proposed models are validated in 33-bus and 135-bus test systems. The results show that the installation of SOPs significantly improves the service restoration under cyberattacks. Both the number and location of SOPs influence the extent of restored service, and differing SOP allocation schemes may lead to similar restoration outcomes. The proposed models and techniques could also be extended to deal with other similar problems in industrial cyber-physical systems.