The Influence Of Formation For Corrosive Sulfur And The Mechanism Of Electrical Equipment Falut

The transformer is one of the key equipments for power delivery and distribution in power system. Huge economic loss and serious social security can be led by transformer faults. In this decade, insulation faults of power transmission and transformation equipment caused by sulfur corrosion attract the attention from academic and industrial researchers. The standards have been developed by the GIGRE to limit the sulfur content of insulation oils, which could certainly avoid winding sulphur corrosion. However, the failure in oil-paper insulation caused by sulfur corrosion products can eventually result the equipment faulty. Recently, much more work has been done to study the mechanism of sulfur corrosion products generation. It is academic meaningful and engineering rewarding to study the influence of the various factors for corrosive products formation in oil-paper insulation, as well as exploring equipment failure mechanism resulted by deposition of corrosive sulfur products.In this paper, the influence of the various factors(the concentration of dibenzyl disulfide(DBDS), temperature, electric field,acid value) for corrosive products formation in oil-paper insulation was studied. Meanwhile, the effect for the oil-paper characteristic was also investigated. Then, mechanisms of power equipment failure for partial discharge and local overheating caused by sulfur corrosion products have been gained. The main research contents of this paper are presented as follows:① The influence of the various factors(the concentration of dibenzyl disulfide(DBDS), temperature,electric field,acid value) for corrosive products formation in oil-paper insulation was studied. Physicochemical parameters and electrical properties of oil-paper insulation were measured. The micro-condition of the copper winding and insulation paper were characterized. And corrosion products on the surface of the insulating paper and that dissolved in oil were obtained. All factors could accelerate the formation of sulfur corrosion products in oil-paper.② The mechanisms of power equipment failure for partial discharge and local overheating caused by sulfur corrosion products have been achieved. Under AC condition, PDIV dropped because of higher dielectric constants caused by the deposition of corrosive products. The partial discharge increased too. Under DC condition, more deep trap and charge in insulation paper possessed due to the deposition. The mechanism of local overheating for insulation paper was also considered. The thermal conductivity of insulation paper reduced after the deposition. Then, local overheating could be presented, which accelerated thermal aging of insulation paper. Similarly, thermal stability of insulation paper also proved the mechanism.