In high-voltage transmission lines, the insulator is one of the most important components. One of the important factors which could increase the electrical conductivity is the condensation of fog and dew on the surface of the contaminated insulators. In this paper, initially, the condensation mechanism of moisture on the insulators’ surface due to radiative cooling has been studied. The soil samples as sources of contamination were collected from the dust centers, followed by chemical analysis and electrical conductivity measurements. The most polluted soil sample was selected for modeling and testing the leakage current. Based on the material properties used in the silicone rubber insulator (230- kV) and the contamination caused by the dust and fog, a simulation study was performed by COMSOL Multiphysics software. According to the conductivity of the contamination layers, leakage current and temperature distribution on the surface have been measured with simulations and experimentally verified. The results show that the leakage current increases with increasing conductivity and thickness of the contamination layer on the insulator. The simulation results are in a close agreement with the experimental data. This makes us believe that modeling the insulator using the commercial software provides reliable results.

在高压输电线路中，绝缘子是最重要的组件之一。可能会增加电导率的重要因素之一是受污染的绝缘子表面上的雾和露水的凝结。本文首先研究了由于辐射冷却而导致的绝缘子表面水分凝结的机理。从尘埃中心收集土壤样品作为污染源，然后进行化学分析和电导率测量。选择污染最严重的土壤样品进行建模和测试泄漏电流。根据硅橡胶绝缘子（230-kV）中使用的材料特性以及粉尘和雾气造成的污染，使用COMSOL Multiphysics软件进行了仿真研究。根据污染层的电导率，通过模拟测量并通过实验验证了表面上的泄漏电流和温度分布。结果表明，泄漏电流随着绝缘体上污染层的电导率和厚度的增加而增加。仿真结果与实验数据非常吻合。这使我们相信，使用商业软件对绝缘子建模可以提供可靠的结果。仿真结果与实验数据非常吻合。这使我们相信，使用商业软件对绝缘子建模可以提供可靠的结果。仿真结果与实验数据非常吻合。这使我们相信，使用商业软件对绝缘子建模可以提供可靠的结果。