As a kind of sulfur antioxidant in mineral insulating oil

dibenzy1 disulfide（DBDS） is also an efficient antioxidant in oil-paper insulation. To investigate the comprehensive effects of the corrosivity and the oxidation resistance of DBDS on the properties of oil-paper insulation

oil samples with different DBDS concentrations(0～200×10

–6

) were prepared and used to perform thermal aging experiments together with insulation windings at 130 ℃ under the condition of nitrogen for 480 h. After the aging experiment

we observed the corrosion morphology of the surface of copper strip and insulating paper after disintegration of the insulation winding

measured and analyzed the properties of di

electric loss

resistivity volume

acid value and copper content

and investigated the starting oxidation temperature and the functional groups of different oil samples. Moreover

we discussed the comprehensive effects of the corrosivity and the oxidation resistance of DBDS on the aging characteristics of insulating oil. Experimental results show that when the insulating oil contains less than 25×10

–6

DBDS

and the antioxidant effect of DBDS is dominant. The oxidation stability of insulating oil will be improved

the performance of oil is better than that of samples excluding DBDS

and the corrosive effect of DBDS will be greater than its antioxidant effect when the insulating oil contains more than 25×10

–6

DBDS. Copper ions and acid will be accelerated due to the corrosion reaction

which will accelerate the aging of oil.