Crosslinked polyethylene (XLPE) and oil paper insulation are both important cable insulation materials

and dielectric performance is a key parameter for measuring the state of insulation ma-terials. Research has shown that temperature can affect the dielectric parameters of insulation materials

but the mechanism of temperature's influence on the dielectric parameters of cable in-sulation materials is still not in-depth. To clarify the influence of temperature on the dielectric properties of different cable insulation materials

this article first measured the dielectric con-stants of XLPE and oil paper insulation at 25 ℃

35 ℃

and 45 ℃ through experiments. It was found that the relative dielectric constant of XLPE decreased with increasing temperature

with a de-crease of 0.28% from 25 ℃ to 35 ℃ and a decrease of 0.49% from 35 ℃ to 45 ℃; The relative die-lectric constant of oil paper insulation increases with temperature

increasing by 2.63% from 25 ℃ to 35 ℃ and 1.73% from 35 ℃ to 45 ℃. Using molecular simulation to analyze this phenomenon

the molecular structures of two materials were constructed

and the relative dielectric constants of materials at different temperatures were calculated using dipole moments. The simulation results were consistent with the experimental results. To further explain the variation law of dielectric constant with temperature

simulation analysis was conducted on the end distance of two materi-als. It was found that the end distance of XLPE molecular chains in a high elastic state increases with temperature

hindering the polarization process and reducing the dielectric constant. The molecular chain end distance of insulating paper

a polar material in the glassy state of oil paper insulation

gradually decreases with increasing temperature

polar motion strengthens

and the relative dielectric constant also increases

explaining the experimental phenomenon from a mechanistic perspective.