PDC patterns of biodegradable transformers insulation oil after experienced faults and at different moisture levels

The PDC method is a simple and reliable analysis tool to monitor transformer insulation systems. Based on PDC measurements of the biodegradable oil in a healthy oil condition at different moisture levels and after faults (Partial discharge, Overheating and Arcing) fault identification can be achieved by comparing the PDC pattern of an oil sample against the PDC fingerprints. Furthermore, the relationship curves between the oil moisture level toward its conductivity level and measured capacitance value have been established. These curves can be used to predict the oil moisture condition and the fault type.