覆冰地区分裂与扩径导线表面电场特性

输电线路覆冰对电力系统安全运行具有严重威胁，目前已经发展了多种防冰除冰方法，但每种方法都有其局限性，对于一些具有微气象、微地形特征的重覆冰地区尚未有较好的解决方法。文中考虑到扩径导线的特点和分裂导线输电线路的局限性，根据波阻抗和自然功率将分裂导线等效为单导线，并考虑电流的集肤效应，得到了等效的单根扩径导线，进而分析比较覆冰地区的分裂导线及其等效的单根扩径导线的表面电场特性。研究表明：等效前后导线截面面积相同且波阻抗一致时，扩径导线与分裂导线相比，不仅显著降低了子导线根数和输电线路的覆冰荷载，而且在扩径导线的半径等于分裂导线的等效单导线半径时，扩径导线的表面最大电场强度小于分裂导线。因此，在严重覆冰地区，采用分裂导线等效半径的扩径导线具有非常好的表面电场特性，且可显著降低冰风荷载，提高抗冰强度。

Surface electric field characteristics of bundle wire and expanded wire in icing area

The icing disaster of transmission line poses a serious threat to the safe operation of power systems. Currently, a variety of anti-icing and de-icing methods have been developed, but each method has its limitations. Particularly, serious icing areas with micro-climate and micro-topography characteristics lack effective solutions. This paper takes into account the characteristics of expanded conductors and the limitations of bundle conductor transmission lines. By considering wave impedance, natural power, and accounting for the skin effect of current, the split conductor is equivalently transformed into a single conductor, and the equivalent single expanded conductor is obtained. Subsequently, the surface electric field characteristics of the split conductor and its equivalent single expanded conductor in icing area are analyzed and compared. The findings reveal that when the total conductor cross-sectional area of the conductor cross-section before and after the equivalent remains the same and the wave impedance is equal, the expanded conductor, compared to the bundle conductor, not only significantly reduces the number of sub-conductors and the icing load on the transmission line, but also the maximum electric field intensity on the surface of the expanded conductor is lower than that of the bundle conductor when the radius of the expanded wire is equal to the equivalent single wire radius of the bundle conductors. Therefore, in severely icing areas, the expanded wire with an equivalent radius to that of the bundle conductors exhibits excellent surface electric field characteristics, significantly reducing ice wind load and improving anti-icing capacity.