【摘要】 电介质在生产和使用过程中通常会受到各种应力的作用,而应力作用与电介质的老化和击穿密切相关。本文利用电子束辐照的方法将空间电荷引入聚甲基丙烯酸甲酯(PMMA)和低密度聚乙烯(LDPE)样品中,在无外加电场下通过外加应力,可能诱发空间电荷脱陷导致树枝化击穿。讨论了应力诱发空间电荷击穿的机理,分析了影响应力诱发的空间电荷击穿的诸多因素,如样品中空间电荷分布情况,机械应力的作用形式(如压缩应力或是拉伸应力),样品中的水份,样品的介电常数等因素在空间电荷树枝化击穿过程的作用。更多还原

【Abstract】 Dielectrics might suffer various kinds of mechanical stress from the processes of manufacture and application, while the mechanical stress had significant effect on the degradation and break down of dielectrics. It was found that mechanical stress could induce space charge breakdown. In this paper, space charge is introduced into polymethyl methacrylate (PMMA) and low density polyethylene (LDPE) samples, and applied mechanical stress is utilized to induce the captured space charge to detrap and possibly lead to space charge breakdown. The mechanism of space charge breakdown induced by applied mechanical stress is discussed. Many factors, such as space charge distribution in the samples, tensile or compressive mechanical stress, content of water in the samples, dielectric constant that affected the space charge breakdown behavior induced by applied mechanical stress, are also discussed in details in this study.更多还原