Application of Comprehensive Relational Grade Theory in Expert System of Transformer Fault Diagnosis

The fault diagnosis of power transformer is an important guarantee technique for safe and reliable running of power system. Combining the dissolved gases analysis and grey relational theory, a new comprehensive relational grade theory is given, which combines grey area relational grade and grey slope relational grade. The method is applied to expert system of transformer fault diagnosis and improves effectively the running and maintenance of power transformer. The paper introduces the concept of example reasoning. By calculating the relational grade between detected data and normative mode vector in source sample database, the fault style can be confirmed. The database and repository in this expert system is an open system. New fault sample can be added into the system, and repository can be classed and modified by experts.