Study on protective effect of metal passivator TTA on the oil-paper insulation system with multiple sulfides

In this paper three sulfides were selected: benzothiophene, disulfide dibenzyl and hexadecyl mercaptan. Passivators were used to investigate the protective effect of passivators on oil-paper insulation systems containing multiple sulfides. Parameters such as shear viscosity, mean square displacement, cohesion energy density and hydrogen bonding number were measured by molecular dynamics simulations of the reactions. The results show that the protective effect of TTA on insulating oil containing sulfides is DBDS > BT > mixing of three sulfides > mixing of two sulfides > HDM, and the protective effect on insulating paper is DBDS > BT > HDM > mixing of three sulfides > mixing of two sulfides. The characteristic parameters of the aged insulating oil, such as acid value and breakdown voltage, were then measured using accelerated thermal ageing experiments. Comparison of the results of the thermal ageing experiments with those of the simulations shows that the effect of TTA on the electrical properties of the insulating oil is consistent. It can be concluded that TTA is insoluble in oil, so it has a great effect on the quality of insulating oil, but has no effect on the quality of insulating paper. It is recommended that TTA be added to transformers together with antioxidants.