我国北方内陆地区线路与变电站用绝缘子的直、交流自然积污试验结果的比较

文章总结了我国北方内陆地区三个直流自然积污试验站的试验结果,分析了盘形绝缘子和支柱绝缘子的直流自然积污特性及其自清洗性能.指出内陆地区秋末至第二年春季为绝缘子表面污秽迅速增长期,夏季的暴雨可有效地清洗绝缘子.经分析自然积污试验结果知:轻污区盘形绝缘子直、交流积污比为2,支柱绝缘子的为3;常年植被覆盖地区绝缘子的直、交流积污比偏小.指出设计直流外绝缘时需考虑绝缘子伞裙上、下表面污秽的不均匀分布、灰密与盐密的比值、可溶盐的成分以及污秽物的粒度等因素的影响.

COMPARISON OF NATURAL CONTAMINANTS ACCUMULATED ON SURFACES OF SUSPENSION AND POST INSULATORS WITH DC AND AC STRESS IN NORTHERN CHINA'S INLAND AREAS

The exposure test results of natural contaminants accumulated on the surfaces of cap, pin and post insulators at three testing stations in northern China's inland areas are summarized. The contaminants growth rapidly from the end of autumn to next early spring, and heavy rain in summer can wash away a lot of contaminants from insulator surfaces. Different insulators have different ratios of contamination degree under DC stress to under AC stress: the contamination ratio for cap and pin insulator is 2 and that for post insulator is 3. But the contamination ratio of DC stress to AC stress is less than 2 in good vegetation areas. Influence of two ratios of NDD to ESDD and ESDD on top surface to that on bottom surface, the chemical compositions of soluble salts and the sizes of contaminant particles must be regarded in the outdoor insulation design.