The importance of particle dispersion in electrical treeing and breakdown in nano-filled epoxy resin
The importance of particle dispersion in electrical treeing and breakdown in nano-filled epoxy resin
复制标题
DOI：
10.1016/j.ijepes.2021.106838
复制
发表时间：
2021-02-11
影响因子：
5.2
通讯作者：
Clancy, Adam J.
中科院分区：
文献类型：
--
作者：
Chen, Siyuan;Rowland, Simon;Clancy, Adam J.
添加纳米填料已被广泛提出作为增强高压聚合物绝缘介电性能的方法，尽管文献中的报道褒贬不一。在这里，二氧化硅纳米粒子的潜力，以延长时间失败，特别是通过电阻在环氧树脂中的电树生长被确定。在配混之前硅烷处理纳米颗粒的益处在减缓树生长和随后的失效时间方面清楚地确立。在实验室中用1、3和5wt%纳米填料的加载量测量针-平面样品中的树木的生长。在所有情况下，平均失效时间都延长了，但在配混之前对纳米颗粒进行硅烷处理产生了更优越的上级结果。树生长前出现一个明显的起始时间也注意到较高的填充，硅烷处理的情况下。硅烷处理的5wt%填充材料的平均失效时间是未填充树脂的28倍。具有未处理的和处理的填料的纳米复合材料之间的性能的改善归因于在处理的情况下填料的更少的附聚和改善的分散。局部放电（PD）的测量结果表明，在处理和未处理的情况下，在树木生长过程中的PD模式的显着差异。这种区别可以提供用于监测材料的质量控制方法。特别是，在硅烷处理的病例中观察到长时间未测量PD。在未填充的材料中的树木生长的视觉成像允许随着树木的生长观察到树木从细到树再到暗树的变化性质。相应的PD测量表明，黑暗的树逐渐成为导电的，和最大PD测量的增长是依赖于树的生长和其碳化的相对速率。X射线计算机断层扫描确定显着差异，平均树通道直径（从2.8？m到2.0？m，对于1重量%和3重量%的情况）。这意味着，除了树的长度变化，蒸发树的体积也发生变化，可以解释观察到的局部放电特性的变化。
The addition of nano-fillers has been widely proposed as a method to enhance the dielectric properties of high voltage polymeric insulation, though there are mixed reports in the literature. Here the potential of silica nanoparticles to extend the time to failure specifically through resistance to electrical tree growth in epoxy resin is determined. The benefit of silane treating the nano-particles before compounding is clearly established with regard to slowing tree growth and subsequent time to failure. The growth of trees in needle-plane samples is measured in the laboratory with loadings of 1, 3 and 5 wt% nano-filler. In all cases the average times to failure are extended, but silane treatment of the nano-particles prior to compounding yields much superior results. The emergence of a pronounced inception time before tree growth is also noted for the higher-filled, silane-treated cases. The average time to failure of silane-treated 5 wt% filled material was 28 times that of the unfilled resin. The improvement in performance between the nanocomposites with untreated and treated fillers is attributed to fewer agglomerations and improved dispersion of the filler in the treated cases. Measurements of Partial Discharge (PD) indicated significant differences in PD patterns during the growth of trees in the treated and untreated cases. This distinction may provide a quality control method for monitoring materials. In particular, long periods in which PDs were not measured were observed in the silane-treated cases. Visual imaging of tree growth in the unfilled material allowed the changing nature of the tree from fine to tree to dark tree to be observed as it grew. Corresponding PD measurements suggest the dark tree is gradually becoming conductive, and that growth of maximum PD measured is dependent on the relative rates of the growth of the tree and its carbonization. X-ray computer tomography identified significant differences in average tree channel diameters (a reduction from 2.8 ?m to 2.0 ?m for 1 wt% and 3 wt% cases). This implies that in addition to tree length changes, evaporated tree volumes also change and may explain the change in partial discharge characteristics observed.