Effect of corrosive sulfide deposition on thermal conductivity of insulating paper

As transformer accidents occur frequently, one of the main reason for such accidents has been confirmed after the disassemble researches with the deterioration of oil-paper insulation caused by the existence of corrosive sulfide. Taking this situation into consideration, a volume of researches have been undertaken in this paper to understand the effect of different dibenzyl disulfide (DBDS) concentration on the formation of corrosive products and its influence on paper insulation, in sulfur corrosion experiments for 3 days at 150 °C temperature, according to the IEC 62535 standard. It turns out that in the process of experiments, corrosive sulfur which slowly deposits on the surface of the insulating paper, causes the decline of both the coefficient of thermal conductivity and thermal capacity of insulating paper. As a result of it, local overheating will accelerate sulfur corrosion and enhance the deposition on the surface of the insulating paper, conversely leading to the degradation of thermal conductivity and thermal capacity of insulating paper.