Intelligent diagnosis method of relay protection defects based on Bayesian theory

The healthy and reliable operation of relay protection devices is of great significance for improving the safe and stable operation of the power grid. Defect analysis of relay protection devices relies on manual experience. Defect diagnosis takes a long time, which leads to a long time exit of protection during defect. The existing intelligent defect diagnosis methods are carried out on a case-by-case basis, which limits the wide-scale application. This paper proposes a fault diagnosis method for relay protection devices based on Bayesian theory, establishes the correlation between the typical fault phenomenon of relay protection device and the defect diagnosis result, and derives the most likely defect result based on the defect phenomenon, with satisfactory defects diagnosis accuracy rate, which plays an important role for operators to quickly diagnose relay protection defects and improves the reliable operation status of protection devices. A practical example is used to verify the effectiveness of the method in this paper.