高速沙尘环境对针-板电极击穿电压的影响

Breakdown Voltage of Needle-plate Air Gaps in High-Speed Sand Environment

为了探明沙尘环境下高速列车车顶绝缘部件闪络机理,依托自建的风洞试验系统进行了沙尘环境下针-板电极间隙击穿试验,通过分析沙尘浓度、风沙速度、间隙距离、沙粒粒径等因素对间隙击穿电压的影响,揭示了高速沙尘环境对间隙放电影响的基本规律。结果表明:间隙击穿电压随沙尘浓度的增加而下降,随间隙距离的增加而增加;有风有沙和有风无沙条件下击穿电压均随着风速的增加呈先上升后下降的趋势,且有风有沙下的击穿电压比有风无沙下的低;随着沙粒粒径的增加,击穿电压先下降后上升,存在极小值。以上研究为沙尘环境中高速列车车顶高压绝缘提供理论基础。

To ascertain the flashover mechanism of external insulations on train roof in a high-speed airflow environment, we investigated the breakdown characteristics and mechanism of short needle-plate air gaps in high-speed airflow based on an artificial experimental wind-tunnel platform. We obtained the breakdown characteristics regularity of the air gaps in wind sand environment by studying the influences of sand mass concentration, wind speed, gap distance and sand diameter on the breakdown voltage. It is found that the breakdown voltage of air gaps decreases with the increase of the sand mass concentration, and increases with the increase of the gap distance. When the wind speed increases, the breakdown voltages in weather of wind dust and wind both appear to be a curve which increases at first and then decreases, and the breakdown voltage in weather of wind dust is lower than the other. The breakdown voltage decreases first and then increases with the increase of the sand mass concentration, and there is a minimal value. Research results can provide a theoretical basis for protection of roof external insulation in a high-speed airflow environment.