Measurement data analyses using an expert system for oil-paper insulation evaluation

Diversification of tests and measurements for inspecting the state of the transformer unit insulation in operation, in order to establish the maintenance optimal strategy for increasing the safety in operation of this equipment, requires new diagnosis methods and insulation condition assessment like the recovery voltage method (RVM) and the polarization and depolarization current (PDC) measurement. Complexity of the transformer insulation structure and degradation mechanisms require special knowledge and experience. In this paper, an expert system (ES) is developed to bring insulation condition assessment procedure accessible to maintenance engineers.