硅橡胶表面离散水珠电场分布及其影响因素研究

Electric Field Distribution and Influencing Factors of Discrete Water Droplets Over Silicone Rubber Surface

高湿热地区常出现降雨和晨间凝露现象,使得输电线路复合绝缘子表面较长时间存在细小水珠。外施电场存在时,水珠三介质交界点处电场强烈畸变,可造成复合绝缘子硅橡胶材料表面电晕放电和憎水性降低进而导致老化加剧,严重时可引起沿面闪络。本研究基于有限元多物理场仿真软件建立了三维模型,采用有限元方法和控制变量法仿真研究了水平背景电场下硅橡胶表面离散水珠对电场分布的影响以及水珠体积、水珠个数、水珠间距、水珠静态接触角等参数对电场畸变程度的影响。此外,通过实际水珠试验解释了水珠在交流电压下形变引起的电晕放电变化过程,为进一步分析水珠电晕放电发展到沿面闪络提供了参考依据。

In high humidity and temperature environment,raining and morning condensation are usual to leave small water droplets on the surface of composite insulator in transmission line.At the junction of three media around the water droplet under external electric field,it is easy to occur strong distortion of electric field,resulting in corona discharge and loss of hydrophobicity on the surface of silicone rubber material of composite insulator,which will lead to accelerated aging and surface flashover.In order to investigate the influencing factors of water droplet corona discharge,it is necessary to simulate the electric field near water droplets,and investigate the influence of water droplets separated on silicone rubber surface on the electric field distribution under horizontal electric field.The influence of four physical parameters such as water droplet volume,number,spacing and static contact angle on the degree of electric field distortion is studied.A 3D model is established based on multi-physical field simulation software.The electric field distribution under different physical parameters is calculated using the finite element method and control variable method.The electric field enhancement factor is calculated,and the change process of corona discharge caused by the deformation of water droplets under AC voltage is explained based on results of simulation and experiments.The results can provide a reference for further explanation and analysis of the development of water droplet corona discharge to surface flashover.