Flashover of ice-covered insulators seriously affects the safe operation of transmission lines. It is necessary to study the electric field distribution for flashover analysis of ice-covered insulators. The electric field of ice-covered insulators was mostly calculated by a two-dimensional (2D) axisymmetric model that cannot be well corresponded to actual icing situations. In this study, a 3D electric field simulation model of ice-covered suspension insulators under moderate icing condition with applied DC voltage was established. Two characteristic parameters, E av and E max were proposed to measure electric field distortion degree. Based on the simulation results, the effects of water film conductivity, icicle length, icicle deviation angle, and icicle distribution on E av and E max were studied. The results showed that icicles have a significant influence on the electric field distribution of insulators. E av increases with the increase of icicle length and decreases with the increase of icicle deviation angle. E max increases with the increase of the icicle length, icicle spacing and adjacent icicle length difference. When the icicle deviation angle is 45°, E max is the largest. Lastly, the possible flashover paths were analysed based on the simulation results, which would provide a theoretical basis for building a flashover model of ice-covered insulators.

中文翻译：

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覆冰悬式绝缘子的三维电场模拟和闪络路径分析

覆冰绝缘子的闪络会严重影响输电线路的安全运行。有必要研究电场分布，以对覆冰绝缘子进行闪络分析。覆冰绝缘子的电场大部分是通过二维（2D）轴对称模型计算的，该模型无法很好地适应实际的结冰情况。在这项研究中，建立了在中等结冰条件下施加直流电压的覆冰悬浮绝缘子的3D电场仿真模型。提出了两个特征参数E av和E max来测量电场畸变度。基于仿真结果，研究了水膜电导率，冰柱长度，冰柱偏离角和冰柱分布对E av和E max的影响。结果表明，冰柱对绝缘子的电场分布有很大影响。E av随着冰柱长度的增加而增加，而随着冰柱偏离角的增加而减小。E max随着冰柱长度，冰柱间距和相邻冰柱长度差的增加而增加。当冰柱偏离角为45°时，E max最大。最后，基于仿真结果对可能的闪络路径进行了分析，为建立覆冰绝缘子的闪络模型提供了理论基础。当冰柱偏离角为45°时，E max最大。最后，基于仿真结果对可能的闪络路径进行了分析，为建立覆冰绝缘子的闪络模型提供了理论基础。当冰柱偏离角为45°时，E max最大。最后，基于仿真结果对可能的闪络路径进行了分析，为建立覆冰绝缘子的闪络模型提供了理论基础。