Abstract: In response to the characteristics of the complex communication network architecture,hierarchical partitioning,dual-network redundancy,and high degree of logical coupling of the new generation of independent and controllable substations,a fault tree modeling and evaluation method oriented to the characteristics of communication function failures is proposed.This method combines the partition structure,equipment redundancy configuration,and multi-path forwarding mechanism of the communication network to construct a multi-level fault logic model covering key units such as the station control layer,spacer layer,isolation device,firewall,etc.It systematically characterizes the typical fault propagation paths and coupling logic of the communication network of the autonomous controllable substation,and combined with engineering examples,quantitatively analyzes the communication availability of the autonomous controllable substation and identifies key fault nodes.Test results indicate that after the introduction of dual-link redundancy and isolation mechanisms,the availability of communication functions in the Core Business Security Zone I reaches 99.85%,the overall availabi-lity of typical interval devices remains above 99.6%,and the overall availability of the entire station communication system reaches 96.53%.The quantitative analysis results show that the dual-network redundancy and partition isolation architecture of the new generation of autonomous controllable substations have advantages in communication reliability,and ensure their comprehensive level in a wider range of business scenarios.

Key words: Substation, Fault tree model, Autonomous and controllable, Communication networks, Reliability assessment