Influences of temperature on partial discharge behaviors in oil-paper bounded gas cavity under pulsating DC voltage

Valve-side windings of high voltage converter transformers withstand voltage stresses, including AC, DC, and strong harmonic voltages. Partial discharges (PDs) happen easily in oil-paper bounded cavities and are significantly influenced by temperature. An artificial cavity discharge model was designed to generate PDs under pulsating DC voltage at several different temperatures in this work. The influences of temperature on PD behaviors in the gas cavity bounded in oil-paper insulation under pulsating DC voltage were investigated. The experimental results show that the temperature exerts a great effect on the characteristics of cavity discharges under pulsating DC voltage and it will accelerate damage to oil-paper insulation from PDs.