Study on the Influence Mechanism of Voltage on Sulfide Corrosion in Power Transformer

At present, only the deterioration effect of electric field on insulating oil under oil-sulfur corrosion has been studied, but the deterioration of insulating paper has not been studied. Therefore, two sulfides, dibenzyl disulfide and dodecyl mercaptan, were selected in this paper. The effect of electric field on insulating paper under oil corrosion was studied by measuring elastic modulus and molecular chain motion of cellulose using reaction molecular dynamics simulation technique. Then the ball plate electrode was used to apply 2 times the initial discharge voltage, and aged in a 150 °C electrothermal aging chamber for 24 h. Another group of control group was set up without electric field. The final results showed that the breakdown voltage, polymerization degree and moisture mass fraction of insulating paper decreased. This verifies the correctness of the simulation from macroscopic experiment. The results show that the addition of electric field will accelerate the process of oil sulfur corrosion, resulting in the deterioration of the performance of the oil paper insulation system.