Abstract:Icing disaster of transmission line was a serious threat to the safe operation of the power system. Currently, a variety of anti-icing and de-icing methods have been developed, but each method has its limitations. There was no good solution for some serious icing areas with micro-climate and micro-topography characteristics. This paper takes into account the characteristics of expanded conductors and the limitations of bundle conductor transmission lines. According to the wave impedance and natural power, the split conductor is equivalent to a single conductor, and considering the skin effect of current, the equivalent single expanded conductor is obtained, and then the surface electric field characteristics of split conductor and its equivalent single expanded conductor in icing area are analyzed and compared. Studies have shown that when the total conductor cross-sectional area of the conductor cross-section before and after the equivalent is the same and the wave impedance is the same, compared with the bundle conductor, the expanded conductor not only significantly reduced the number of sub-conductors and the icing load of transmission line, but also when the radius of the expanded wire was equal to the equivalent single wire radius of the bundle conductors, The maximum electric field intensity on the surface of the expanded conductor is smaller than that of the bundle conductor. Therefore, in severely icing areas, the expanded wire with the equivalent radius of the bundle conductors had very good surface electric field characteristics, which could significantly reduce the ice wind load and improve the anti-icing capacity.