Automated analysis of protective relay data

Validation and diagnosis of relay operation is very important to protection engineers in fault analysis. This paper presents development of an expert system based automated analysis solution, which performs validation and diagnosis of digital protective relay operation in great detail by analyzing data contained in various relay reports and files. In the system, forward chaining reasoning is used to predict relay behavior while backward chaining reasoning is used to diagnose the reasons for inconsistency between expected and actual relay behavior. An example is given to demonstrate the capability of the prototype system.