强电场下高聚物绝缘中的应力转化与补偿效应

Conversion and Compensation Effects of Stress in High Polymer Insulating Materials under High Electrical Field

研究了高分子聚合物绝缘材料在强电场下发生的应力转化与补偿现象。发现外加电场可以转化为材料耐受的机械应力,形成机械应变;反之,外加机械应力或残余应力又可以补偿电场作用,影响材料的击穿电压和场强。这种转化和补偿的定量关系与材料的松弛特性有关,由此导出的材料击穿场强公式可用于定量评估应力/应变以及杨氏模量对材料介电性能的影响。

The stress conversion and compensation effects in high polymer insulating materials under high electrical field have been studied. The results reveal that electrical field applied can be converted to mechanical stress, so as to cause mechanical strain in dielectrics. Contrarily to this process, applied or residual mechanical stress can compensate the electrical field, causing the insulating materials to break down at lower fields. This stress conversion and compensation phenomenon is found to rely on the relaxation characteristics of the dielectrics, and the breakdown field formula deduced accordingly can be used to assess the effect of mechanical stress/strain or Young＇s modulus on dielectric properties of the high polymer insulating materials.