Security-Oriented Cyber-Physical Risk Assessment for Cyberattacks on Distribution System

With the increasing deployment of advanced sensing and measurement devices, the modern distribution system is evolved into a cyber-physical power distribution system (CPPDS). Due to the extensive application of information and communication technology, CPPDS is prevalently exposed to a wide range of cybersecurity threats. In this paper, a novel security-oriented cyber-physical risk assessment method for CPPDS is proposed. Based on the information model composed of logical nodes, an attack graph of privilege promotion by exploiting the cyber vulnerabilities is constructed. The physical consequence caused by cyberattack is analyzed in detail. By using the Markov decision process (MDP) theory, the cyber-physical risk index (CPRI) is calculated. Furthermore, considering the allocation of the finite defense resource, the modified MDP approach with an attack-defense game is presented. The effectiveness of the proposed method is demonstrated with case studies on a four-feeder IEEE-RTBS test system.