输电线路导线覆冰严重威胁着电网安全运行,导线覆冰过程复杂,影响因素众多,对其覆冰增长规律的准确掌握是建立并优化导线覆冰数值计算模型的基础。本文从自然覆冰试验出发,依托雪峰山自然覆冰试验基地对不同种类的导线进行了自然覆冰观测试验,研究了导线直径、导线表面处理情况、覆冰类型及导线扭转对导线覆冰增长过程的影响。通过导线表面水滴碰撞系数的计算分析了不同直径导线覆冰的差异性。研究结果表明：自然环境条件下,风速对导线雾凇覆冰冰形起决定性作用,覆冰主要在导线迎风面(横向迎风侧)累积,而背风侧和纵向覆冰较少。覆冰厚度随时间非线性增长,导线直径越小,覆冰厚度增长越快。导线扭转使得导线背风侧向迎风侧转变,覆冰厚度增长速率加快。雨凇覆冰时,除迎风侧翼型覆冰外,导线下方易冻结形成冰棱,使得冰形结构更为复杂。

The icing of transmission lines seriously threatens the safe of power grid. The icing process of transmission lines is complicated and there are many influences. The accurate understanding of the law of icing is the basis for the establishment and optimization of a icing numerical model. Based on natural icing tests, the tests of different kinds of conductor are carried out on Xuefeng mountain natural icing test base, and the influences of conductor diameter, conductor surface treatment, icing type and torsion on icing process are studied. The characteristics of icing on conductors with different diameters are analyzed by calculating the water droplet collision efficiency. The results show that under the natural environment, the wind velocity is the key factor which determines the rime shape on transmission lines. Meanwhile, the icing thickness increases nonlinearly with time, the smaller the conductor diameter, the faster the icing thickness increases. The conductor torsion makes the leeward side of conductor changes to the windward side, which increases the icing rate. When the icing type becomes glaze, in addition to the windward wing ice, there are more likely icicles freezing under a conductor, as a result, the ice structure becomes more complex.

TM85