Network Security Risk Assessment of CPS System in Distribution Network Based on Attack Graph

With the development of advanced information and communication technology and intelligent control technology, the modern distribution network has gradually developed into a cyber-physical system of the distribution network, which also brings about the impact of information-side network security threats on the coupling failure of the physical-side power grid. In this context, a method for quantitative assessment of the network security risk of the distribution network CPS system suitable for the principle of power security protection is proposed. First of all, the physical architecture model of a typical distribution network information physical system was built; Secondly, for system network attacks, the attack path data stream related to device vulnerabilities is established, the attack behavior process is modeled based on the attack graph, and the series-parallel model is combined to calculate the success probability of attacking the target circuit breaker; Finally, the article takes the loss of load caused by the action of the attack circuit breaker as the physical consequence to quantify the risk value of the system and complete the network security risk assessment of the system.