Abstract: To improve reliability of relay protection system isolation in smart substation, an automatic security isolation strategies generation method based on virtual connection cut set is proposed. This paper first analyzes the necessity of security isolation of relay protection system in smart substation. Then the proposed model is constructed including equipment and associated information models, virtual connection cut set model and relational model between branch and soft strips. Finally, the 110 kV side relay protection system of a 110 kV substation is taken as an example to analyze proposed method. Security isolation strategy analysis results show the effectiveness of proposed method.

Key words: virtual connection, cut set, smart substation, relay protection, security isolation