Research Progress on Electrical Treeing in Epoxy Resin Insulation Materials

This paper presents a comprehensive analysis of the insulation breakdown phenomenon in epoxy resin insulation induced by the degradation of electrical trees, with reference to both domestic and international studies. It elucidates the mechanisms of electrical tree initiation and degradation in epoxy resins by drawing on the theories of space charge accumulation and migration, local electric field formation, ultraviolet radiation, and mechanical stress chain breakage. The paper also discusses the operational conditions of the electrical equipment, detailing the effects of superimposed electric fields, temperature gradients, mechanical stresses, magnetic gradients, and humid environments on the insulation degradation of the epoxy resin. Furthermore, it summarizes the correlation between tree growth characteristics and charge transport behavior under the influence of multiple physical fields. To enhance the insulation performance of epoxy resins and ensure the safe and reliable operation of electrical equipment, methods to inhibit electrical tree formation are discussed. These methods include the regulation of the manufacturing process, inorganic doping, and the use of self-repairing materials. The inhibition mechanisms are analyzed at the molecular configuration level and microstructural scale, and from a macroscopic standpoint. This study aimed to provide recommendations for future research on the growth and suppression of electrical trees in epoxy resin based on the current state of knowledge.