AC dielectric strength due to the mixture ratio of LLDPE and EVA

Abstract

In this paper, the AC dielectric strength due to the mixture ratio of a film mixed with linear low density polyethylene (LLDPE) and ethylene vinyl acetate (EVA) was researched. Polyethylene, usually used as the insulating material of power cables, is a non-polar and low dielectric loss polymer. But it has defects of tree generation and accumulation of space charge by an applied voltage, resulting in the decreased life and performance. Therefore, to solve these problems, mixed films of LLDPE and EVA with similar physical properties in the case of low VA contents were made and tested for the mixture ratios of 80:20, 70:30, 60:40 and 50:50[wt%]. We analyzed physical properties and measured the dielectric strength to improve the performance of polyethylene. From the results, specimens of 70:30 and 50:50 were excellent at insulating performance.