Mechanism of the Effect of Copper Sulfide on Partial Discharge of Oil Paper Insulation under Slightly Uneven Electric Field
The reaction of corrosive sulfur present in transformer oil with the copper winding results in the formation of copper sul-fide(Cu2S),and this process is intimately associated with the occurrence of partial discharge(PD)phenomena in power transformers.The development process of partial discharges in oil-paper insulation under Cu2S deposition conditions and its influencing laws were in-vestigated.A hydrodynamic drift-diffusion model and a bipolar charge-carrier transport model were combined to analyze the develop-ment of PD under cylindrical plate electrode geometries.Charge density cloud maps of PD processes in oil-paper system under Cu2 S deposition in slightly inhomogeneous electric field conditions were obtained.As the applied voltage increases,the oil molecules near the column electrode were first ionized into positive ions and electrons,and then the oil molecules near the deposition begin to be ion-ized.An increase in the thickness of Cu2S deposits leads to an elevation in the electric field strength within the oil gap,subsequently exacerbating the discharge phenomenon and resulting in a greater local charge density.The wider deposition of Cu2S promotes the diffu-sion of charge along its surface.The study has revealed the physical mechanisms and operating laws underlying the PD induced by Cu2S deposition in a slightly inhomogeneous electric field,thereby providing a theoretical reference for the further development of suppression techniques for Cu2S deposition-related discharges.
transformerCu2 S depositionoil paper insulationpartial discharge(PD)
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维普
