中文摘要：

为研究污秽物对交流导线起晕电压的影响规律,基于小电晕笼进行单根导线在人工涂污状态下起始电晕特性的试验研究。采用光滑钢管模拟单根导线,分析颗粒度均〈0.15mm的碳颗粒、沙颗粒和高岭土这3种典型的模拟污秽物等效表面粗糙系数对导线起晕电压的影响。首先利用3电极平板电容器,得到试验所用干燥沙颗粒和高岭土的相对介电常数分别为4.3和3.5。电晕特性试验的结果表明：相比较干净状态下,导线涂有相同颗粒大小的沙颗粒、高岭土和碳颗粒时,其起晕电压分别降低了21.76%、10.3%和52.71%。分析认为,污秽物的存在畸变了交流导线表面电场,使得导线起晕电压降低;沙颗粒的相对介电常数比高岭土的大,因此导致导线起晕电压降低较多;导电良好的碳颗粒的存在使导线表面电场畸变得最严重,降低起晕电压也最多。高岭土,沙颗粒和碳颗粒的存在使导线等效粗糙系数分别降低到0.9,0.78和0.48。

英文摘要：

In order to study the influence of contamination on corona onset voltage of AC conductors, corona onset tests of single conductor in artificial contamination condition were performed based on a small corona cage. Using a smooth stainless steel tube as the single conductor, we tested and analyzed the influences of carbon, sand, and kaolin particles, whose sizes were all less than 0.15 mm, on the corona onset voltage of conductor. Firstly, using a three-electrode plate capacitor, we obtained the relative permittivities of sand and kaolin particles to be 4.3 and 3.5, respectively. The results of corona characteristic test showed that, compared with those in clean condition, the corona onset voltages of the conductors containing sand, kaolin, and carbon of the same particle size decreased by 21.76~ ,10.3G, and 52.71~, respectively. It is concluded that the contamination can distort the surface electric field of the AC conductor so as to decrease the corona onset voltage of conductor. Compared with kaolin, sand particles have a relative higher permittivity, thus they reduce the corona onset voltage of conductor more ramarkably; due to their good conductivity, the carbon particles distort the electric field of the conductor to the most degree, hence they reduce the corona onset voltage to the most degree. The existence of kaolin, sand and carbon particle decreases the equivalent roughness factor of the conductor to 0.9, 0.78 and 0.48, respectively.