Assessment of the power transformer insulation system condition by Absorption - Resorption Currents Method

This paper presents some results obtained in RDN (Romanian Distribution Network) to define the condition of 6 power transformers by Absorption - Resorption Currents Method (ABSC). Based on the absorption - resorption currents measurements, a data base on the characteristics of transformers insulation systems has been realized. The condition assessment of oil-paper insulation systems was defined by processing these data (time and frequency domain) and determining the insulation resistance, moisture content, polarisation index, oil and paper conductivities, capacitance, power factor, ageing degree, the residual life cycle, etc. Some of the results obtained by ABSC Method were compared to the values obtained by direct transformer measurement.