哈郑线河南段带电绝缘子污秽成分及悬挂高度对积污的影响

Analysis on Contamination Components of Energized Insulator of Hami-Zhengzhou Overhead Line in Henan and Influence of Installation Height on Pollution Accumulation

为研究特高压线路绝缘子的自然积污状况及不同呼称高度杆塔上绝缘子的积污水平差异,在河南省郑州市境内的±800 k V哈郑直流线路的一基杆塔上,对1片悬挂在负极导线端的绝缘子和4串悬挂于不同高度处的不带电绝缘子进行了半年的自然积污试验。试验结果表明:带电绝缘子表面污秽中的阳离子主要为2aC+和4NH+,阴离子主要为24SO-和3NO-;不可溶成分中2Si O约占80%,也含有少量2 3Al O、2 3Fe O等。工厂烟尘、汽车尾气中的2SO和氮氧化物是绝缘子污秽中24SO-和3NO-的重要来源。利用富集因子法计算得出了污秽中各金属元素的富集程度,发现Ca、Zn、Fe、Mg和Al等元素均受到不同程度的人为污染,其中Ca和Zn元素达到了严重污染的程度。化工厂废液中的2nZ+会通过污染周边土壤间接地影响绝缘子积污。绝缘子表面污秽颗粒粒度集中在10μm左右。同一地区,绝缘子表面自然积污程度随着悬挂高度的增加而逐渐降低。

In order to investigate the natural pollution condition of ultra high voltage（UHV）DC overhead line insulators and the pollution level discrepancy of insulators on different heights, a half-year-period natural pollution experiment was carried out at the site of a trans＋ssion tower of the ±00 kV Hami=Zhengzhou transmission line in Zhengzhou, Henan. On the selected tower hanged a piece of insulator energized by negative voltage and four insulator strings without energized on different heights, The experiment result indicates that in the contaminants on the energized insulator surface the major cations are C2＋ and NH： and the major anions are SO42-andNO3-, the amount of SiO2 accounts for about 80% of the total insoluble components, and the rest includes Al2O3, Fe203 and so on. The SO2 and nitrogen oxides in the plant smoke and vehicle end gas are mainly responsible for the SO42- and NO＋ in the contamination. Through enrichment factor method the enrichment level of each metallic element in the contamination is calculated. It is found that the elements of Ca, Zn, Fe, Mg and AI are all subject to anthropogenic pollution to different degrees. The elements of Ca and Zn is reached a serious level, The ion Z2＋ in the plant waste can pollute the insulator indirectly via spreading out the surrounding soil. The granularity of the contaminants on the insulator surface is mainly distributed around 10 μm. In the same district the natural con＋nation level becomes lower as the insulator hangs higher.