Assessment of the Insulation Conditions of Power Transformers Through Online Monitoring of Partial Discharges

The assessment of the insulation condition of a transformer is of great importance for the operational efficiency of the power system. However, as insulation systems are complex, many challenges are seen in terms of methods of analysis and measurement of critical parameters. In this context, this paper presents the application of an online monitoring system specially developed for the detection of partial discharges (PDs), which are recognized as a phenomenon that carries relevant information regarding the health of a transformer. The results were explored to show how the PD pattern and its correlation with gases dissolved in oil can be analyzed in practical situations with the equipment in service.