Adhesion characteristics of carbon particles on the surface of epoxy resin in insulating oil under DC electric field and influencing factors

Abstract

Abstract The adhesion of carbon particles on the surface of epoxy resin in insulating oil is a significant factor contributing to surface flashover. However, there is currently a lack of a dynamic model that can reasonably explain the adhesion process of impurity particles, and the characteristics of particle adhesion are not yet clear, making it difficult to assess the risks of insulation contamination and surface flashover of valve‐side bushing capacitance core. In this study, based on the Johnson–Kendall–Roberts (JKR) theory and the normal distribution characteristics of particle charges, the adhesion probability model of conductive particles in insulating oil on the surface of epoxy resin under DC electric fields was established, and carbon particle adhesion experiments were conducted to verify the accuracy of the model. The impact of electric field intensity, particle size, particle charge, and surface energy of the insulation material on the adhesion characteristics of carbon particles was investigated using the proposed model. The results can be utilised for the assessment of insulation contamination risks of valve‐side bushing capacitance core and serves as a vital theoretical foundation for guiding the optimisation of anti‐contamination structures in internal insulation and the development of advanced pollution‐resistant and flashover‐resistant insulation materials.