High voltage transformer insulation evaluation using a measurement expert system

Diversification of the range of tests and measurements for inspecting the state of the transformer unit insulation in operation with a view to establishing the maintenance optimum strategy for increasing the safety in operation of this equipment has required new diagnosis method development 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 requires special knowledge and experience. In this paper, an expert system (ES) is developed to bring insulation condition assessment procedure accessible to maintenance engineers.