中文摘要：

覆冰下绝缘子电气性能将降低,国内外采用绝缘子覆冰质量（m）、旋转导体覆冰厚度（D）或绝缘子表面覆冰厚度（d）等表征绝缘子的覆冰程度。为了解覆冰程度对绝缘子冰闪电压的影响,开展了不同覆冰程度下500kV复合绝缘子短样直流冰闪特性的试验研究,分析了绝缘子覆冰质量、旋转导体覆冰厚度和绝缘子表面覆冰厚度对复合绝缘子冰闪电压的影响。结果表明：盐密为0.05mg/cm2且单支绝缘子覆冰质量为5.0kg时复合绝缘子直流冰闪梯度约为77kV/m;m、D或d均可表征绝缘子的覆冰程度,且具有等价性关系,即d=1.06D0.78和m=3.52lnD-5.37。研究结果可为覆冰地区输电线路外绝缘的选择和设计提供参考。

英文摘要：

The electric performance of insulator string may be reduced under ice condition and the mass of ice of insulator （m） , therefore, the ice thickness of rolling conductor monitoring （D） or ice thickness of the surface of insulator （d） is adopted to describe the icing degree of insulator all over the world. We studied the DC icing flashover performance of short sample of 500 kV composite insulator under different icing degrees to know the influence of icing degree on icing flashover voltage of insulator, and analyzed the effects of mass of ice of insulator, ice thickness of rolling conductor monitoring and ice thickness of the surface of insulator on icing flashover voltage of composite in sulator. The test results show that the DC flashover voltage degree is about 77 kV/m under the conditions of 0.05 mg/cm^2 of salt deposit density and 5.0 kg of mass of ice for composite insulator; the equivalent relation between mass of ice of insulator, ice thickness of rolling conductor monitoring and ice thickness of the surface of insulator is d= 1.06D^0.78 and m=3. 521nD- 5. 37 according to the equivalent principle to the flashover voltage of iced-covered composite insulators. The results can offer some references for the external insulation selection and design of transmission lines in ice region.