人工磨蚀对车顶绝缘子沿面放电影响研究

沙尘环境对高速列车的安全运行有很大影响,为研究车顶绝缘子受风沙磨蚀后沿面放电的变化,对车顶绝缘子片进行人工磨蚀试验,观察其表面粗糙度、憎水性及闪络电压的变化。试验结果表明:不同磨蚀时间的试样表面憎水性变化趋势相似,砂纸目数对憎水性变化起主导作用;随砂纸目数增大,磨蚀后绝缘片纵向干闪电压先下降后上升,横向干闪电压呈倒Z字形变化,横向湿闪电压变化规律与纵向湿闪电压均呈U型变化。分析可知:磨蚀引起的爬电距离增大与电场畸变共同作用,影响闪络电压的变化情况。文中通过研究车顶绝缘子憎水性及沿面放电情况受人工磨蚀的影响,揭示了风沙磨蚀对车顶绝缘子沿面放电影响的机理。

Study on the Creepage Discharge of Roof Insulators Due to Artificial Erosion

To investigate the changes in the creepage discharge of high-speed train roof insulators in dust environment,erosion test of the roof insulator was carried out to observe the changes in its surface roughness,hydrophobicity and flashover voltage.Results show that:1)the surface hydrophobicity of the insulator samples with different erosion time is similar,and the sandpaper mesh is the main factor influencing hydrophobicity change;2)with the mesh of sandpaper increasing,the longitudinal insulation dry flashover voltage decreases first and then increases,and the transverse dry flashover voltage increases after the first drop then rises again the variation regularity of the transverse wet flashover voltage is consistent with the longitudinal wet flashover voltage,presenting U-shape.Analysis indicates that the increases of creepage distance and electric field distortion both affect the flashover voltage.In addition,the mechanism of dust erosion affecting the creepage discharge of roof insulators was also revealed.