Reliability Evaluation of Substation Communication Network Based on Fault Tree and Minimum Cut Set Method

Digital substations use communication networks instead of hard wiring to achieve information sharing, but require higher reliability. This article takes the protection system of a classic digital substation as the research object, and uses fault tree and minimum cut set method to calculate its reliability. Firstly, study the three-layer structure of classic digital substations and construct equivalent models of equipment components at each level. Then, based on the equivalent models of each component, a fault tree is drawn, and the minimum cut set is determined through the fault tree. Finally, the reliability of the digital substation protection system is calculated using the minimum cut set method. The calculation example shows that the reliability of the classic digital substation protection system using a dual redundant communication network structure is even better than that of traditional substations.