Trap Distribution and Insulation Characteristics of Epoxy/AlN Nanocomposites for Current Lead Insulation of DC-SFCL

摘要

Epoxy resin is usually used as the current lead insulation in the superconducting fault current limiter (SFCL), which requires low coefficient of thermal expansion of insulating material. This paper investigated the thermal and electrical properties of the epoxy/AlN nanocomposites with different content of AlN. The mass fraction of AlN particles in the nanocomposites were 0, 1, 3 and 5 wt% respectively. The average coefficient of thermal expansion of the sample was measured. Meanwhile, the trap level distribution and breakdown characteristics of samples in LN₂ were calculated by Weibull distribution. The experimental results indicate that the coefficient of thermal expansion of epoxy/AlN nanocomposites is reduced by about 25%. And the trap density increases first and then decreased with the increase of content of AlN.