覆冰对交流导线电晕起始特性影响规律的研究

Influence of Icing to the Corona Inception Characteristics of the AC Power Transmission Lines

中国输电线路走廊不可避免会穿越覆冰区。国内外对于导线电晕开展了长期研究,相对覆冰对交流导线电晕起始特性的影响研究还较少。笔者基于小电晕笼搭建了一套模拟覆冰条件下的导线电晕特性试验平台,采用光滑钢管模拟单根导线进行覆冰试验。通过改变覆冰水电导率和冰凌长度研究不同程度覆冰对导线起晕特性的影响。研究结果表明:在一定范围内,覆冰水电导率对覆冰导线起晕电压影响不大;冰凌使导线表面电场畸变严重,随着冰凌长度的逐渐增加,导线电晕电流也随之显著增大,对应的导线起晕电压和等效粗糙系数明显降低;当冰凌长度约超过18 mm时,起晕电压和等效粗糙系数变化很小,趋于饱和。

The transmission line corridor will inevitably cross the icing area in China. Long-term researches have been carried out on corona characteristics of the conductor. However, studies on effect of icing on transmission line corona inception characteristics are seldom researched at present. This paper presents a platform that can be used to do some researches about that issue. The test is done in the corona cage, in which a smooth stainless steel tube is applied to simulate the single conductor. In order to research the influence of different icing degree to the corona inception characteristics of the conductor, conductor icing test was done with configuring three different conductivity of icing water. The test result shows that the conductivity of icing water has little impact on corona inception voltage of conductor in certain range. Owing to the ice, the distortion of the conductor electric field is serious. With the increase of icicle length, conductor corona current increases significantly, correspondingly,conductor corona inception voltage and equivalent roughness coefficient decrease. When icicle length increases to about 18 mm, the corona inception voltage and equivalent roughness coefficient remain almost unchanged.