Partial Discharge Inception Voltage in Transformer Natural Ester Liquid - Effect of the Measurement Method in the Presence of Moisture

The long term persistent occurrence of partial discharges (PD) may influence the long term stability of insulating liquid. Therefore, the Partial Discharge Inception Voltage (PDIV) is one of the important parameters of the condition of high voltage insulation systems. However, the PDIV is tested using different test methods and electrode configurations. The article aims to show the impact of test methods and electrode configuration on the PDIV measurement of natural ester based transformer oil in the presence of dissolved water.