中文摘要：

与传统变电站继电保护相比，数字化变电站继电保护系统在结构和内涵上都发生了重大改变，其系统可靠性目前尚无标准的评价模型和方法。在分析数字化变电站继电保护系统构成基础上，把信息流划分成同步对时、SV和GOOSE三类，对每类信息流回路可能的拓扑结构进行了分析。然后用最小路集算法对三类信息流回路连通率进行计算，用串并联模型对继电保护系统的整体可靠性进行计算。最后讨论了建模算法的软件实现并进行了算例分析。研究表明，该建模方法为评价继电保护系统不同方案的可靠性提供了有效手段。

英文摘要：

Compared with the traditional substation relay protection, the structure and content of relay protection system in digital substation have changed greatly and there is no standard model and method to evaluate their reliability. Based on the analysis of the constitution of digital substation relay protection systems, the information flow is divided into three kinds, which are time synchronization flow, SV flow and GOOSE flow, and their possible topology for each kind of flow is analyzed. Then it uses the minimal path sets algorithm to calculate the connected rate of three kinds of information flow, and uses series and parallel model to calculate the overall reliability of relay protection systems. At last the paper discusses the software realization of this modeling algorithm, and the example analysis shows that this modeling method provides effective means to evaluate the reliability of different schemes of relay protection systems.