Effects of Temperature Gradients on Breakdown Patterns of AC-GIL Tri-Post Insulators

This paper explores the effects of temperature gradients on the breakdown behavior of tri-post insulators in alternating current gas-insulated transmission lines (AC-GIL). The study uses both experimental and simulation methods to assess how temperature variations impact insulator properties. It is found that increased temperature leads to a decrease in the tensile strength and elasticity of epoxy resin (EP), as well as a slight change in dielectric properties below its glass transition temperature (Tg). Above Tg, the relative permittivity and dielectric loss increase significantly. These temperature gradients affect breakdown times and result in varying failure patterns of the insulators.