摘要
为解决电网中大量运行电缆的水树老化问题,采用一种能生成TiO2无机颗粒的修复液对水树老化交联聚乙烯(XLPE)电缆绝缘进行修复,研究了修复效果和绝缘提升机理。将修复液与水直接反应,利用数字电桥和扫描电镜(SEM)研究生成物的介电性能和微观特征。用水针电极法加速XLPE电缆绝缘水树老化,利用修复液对老化绝缘进行修复,测量了样本的击穿电压。通过SEM和能谱分析(XPS),对水树内的填充物进行了观察和分析。实验结果表明:该修复液能扩散到水树区域消耗水分、生成绝缘性能良好的有机-无机复合填充物填充水树空洞;同时,分析认为生成的大量TiO2颗粒能均匀电场、吸收紫外光、降低热电子加速,使修复后样本的击穿电压高于老化样本和新样本的击穿电压。通过实验研究证明,该修复液不但能修复水树老化电缆绝缘,还能进一步提升老化区域的击穿性能。
We proposed a rejuvenation fluid that rejuvenated water tree aged crosslinked polyethylene （XLPE） cables to deal with the spreading water tree aging problem in urban distribution grids. The fluid reacts with water to form macro molecule polymer and TiO2 inorganic particles. Meanwhile, we investigated its performance and mechanism of enhancing cable insulation. Using a digital bridge and SEM, we studied the dielectric properties and microscopic characteristics of the compounds produced by the direct reaction between the rejuvenation fluid and water. Then, after adopting the rejuve nation fluid to treat water tree aged samples obtained by an accelerated aging experiment, we compared the breakdown voltages of the samples. Also, using SEM and XPS, we observed and analyzed the filling compound in the voids of water trees. The results indicate that the rejuvenation fluid can diffuse into the insulator to eliminate water, and the generated organicinorganic filling compounds have good dielectric properties. Moreover, the breakdown voltage of rejuvenated cables is higher than aged cable or even new cables. This is probably because the TiO2 particles in the filling compounds can inhibit space charge accumulation, help uniform electric field, absorb UV lights, and reduce thermal electron emission It is concluded that the proposed rejuvenation fluid can rejuvenate or even further enhance insulation of aged XLPE cables.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2014年第1期67-73,共7页
High Voltage Engineering
