为降低由于隧道拱顶渗水形成的水柱与腕臂绝缘子之间的间隙击穿概率，提高隧道内供电系统的稳定性，设计一种可改变拱顶渗水下落位置的导流槽结构并分析其对腕臂绝缘子附近电场的影响。构建包含拱顶、水柱和腕臂绝缘子在内的1∶1三维模型并计算其电位、电场分布，分析水柱形貌、水柱长度、水柱位置及导流槽结构等参数对绝缘子附近空间电场分布的影响特性。结果表明： 水柱单端接地且断续时，其最大空气间隙电场畸变率小于水柱通道连续时的空气间隙电场畸变率。自拱顶向下延伸的连续水柱滴落位置距离腕臂绝缘子高压端68 mm时，剩余空气间隙的平均电场强度小于5.66 kV/cm，此时间隙被击穿的概率最大；水柱越靠近绝缘子低压端，水柱表面的电场强度畸变率越小，水柱诱发的间隙击穿概率越小；加装导流槽改变了水柱跌落点，拱顶-高压金具空气间隙的平均电场强度低于5.23 kV/cm。

To reduce the probability of breakdown due to the gap between the water column formed by the seepage of water from tunnel crown and the cantilever insulator, and improve the stability of the power supply system in the tunnel, a seepage deflector structure that can change the location of seepage water falling from the crown is designed, and its effect on the electric field near the cantilever insulator is analyzed. A 1∶1 three-dimensional model containing crown, water column, and cantilever insulator is constructed and its potential and electric field distributions are calculated, thus examining the effects of water column morphology, water column length, water column position, and inflow channel structure on the spatial electric field distribution in the vicinity of the insulator. The results reveal the following: (1) When the water column is grounded at one end and intermittent, its maximum air gap electric field distortion rate is less than that when the water column channel is continuous. (2) When a continuous column of water extending downwards from the crown drops 68 mm from the high-voltage end of the cantilever insulator, the average electric field strength of the remaining air gap is less than 5.66 kV/cm. (3) The closer the water column is to the low voltage end of the insulator, the smaller the distortion rate of the electric field strength on the surface of the water column. (4) The average electric field strength of the air gap from the crown to the high-voltage fittings is lower than 5.23 kV/cm after the addition of a deflector channel to change the drop point of the water column.