交流电场对220kV复合绝缘子覆冰及其闪络特性的影响

Influence of AC Electrical Field on 220 kV Composite Insulators Icing and Flashover Characteristics

为补充完善高电压等级复合绝缘子带电覆冰的研究,以复合绝缘子FXBW-220/100为试品,在大型人工气候实验室对其进行了带电与不带电人工覆冰试验。利用试验结果分析了电场对复合绝缘子覆冰及闪络特性的影响,并针对试验现象给出了合理的解释。结果表明:电场对覆冰绝缘子覆冰的影响主要为电场的极化作用和几种常规放电等带来的热效应;电场的强度、场线的均匀性对复合绝缘子覆冰也有重要影响。带电情况下绝缘子覆冰的其它结论包括:带均压环的绝缘子的高压端不易发生桥接;复合绝缘子大部分伞面覆冰冰层结构密实、光滑、透明;带电情况下雨凇冰棱密度小于不带电情况下雨凇冰棱密度,且随着外加电压的提高而减小;均压环冰棱密度随着外加电压的提高而增加;绝缘子覆冰质量随着外加电压的提高呈先上升后降低的趋势;绝缘子50%闪络电压随着外加电压的提高呈先降低后升高的趋势。

To further research the energized icing of high voltage vacuum composite insulators, taking a composite insulator FXBW-220/100 as the sample, we experimentally investigated both charged and no-charged icing in a multifunctional artificial climate chamber. According to the test results, the influence of electric field on composite insulators＇ icing and flashover characteristics was analyzed, and reasonable explanations for the phenomenon in the experiments were also proposed. The results show that the main influence of the electric field on the ice covering is the heating effect brought by the polarization and several conventional kinds of discharge. However, the electric field strength and the uniformity of the field lines also show deep influences on the icing. Several other conclusions for the composite insulator under charge are as follows ： 1 ） The high-voltage terminal of a composite insulator in the presence of a grading ring does not easily bridge. 2） Most of the ice cover structures on the umbrella shapes of a composite insulator are smooth, dense, and transparent. 3） The icicle density of glaze icing in the presence of charge is less than that in the absence of charge, and it decreases with increasing external voltage. 4） The density of icicles hanging on the grading ring increases with external voltage. 5） The weight of the ice covered on the insulator shows a tendency of ascending at first and then descending when the external voltage increases. 6） The 50% flashover voltage of insulator shows a tendency of descending at first and then ascending when the external voltage increases.