空气间隙击穿后放电通道内气体密度恢复特性

Recovery Characteristics of Gas Density in Discharge Channel After Air Gap Breakdown

空气是电力系统最主要的绝缘介质,但目前空气间隙击穿后相关试验结果的匮乏制约了对绝缘恢复过程的认识。为此采用纹影观测技术,对空气间隙击穿后放电通道的气体密度变化进行观测,分析了放电通道的形态变化特性,并基于纹影图像计算了放电通道不同区域气体密度的恢复程度。试验结果表明:间隙击穿后放电通道的形态由弯变直然后逐渐变得不规则;间隙击穿后放电通道不同区域的气体密度恢复速率有所差异,而且棒电极附近区域的气体密度恢复最快;同时基于文中定义的气体密度恢复程度,在该试验条件下间隙击穿后放电通道气体密度的恢复时间约为200 ms。该试验方法和结果可为重合闸时间中放电通道去游离时间研究提供参考。

Air is the most important insulating medium in the power system,but the lack of relevant experimental results after air gap breakdown currently restricts the understanding of the insulation recovery process.In this paper,the schlieren observation technology was used to quantitatively observe the gas density change of the discharge channel after air gap breakdown,to analyze the morphological changes of the discharge channel,and to calculate the recovery degree of gas density in different areas of the discharge channel based on the schlieren images.The test results show that,after the gap breakdown,the shape of the discharge channel changes from bending to straight and then gradually becomes irregular.The gas density recovery rate in different areas of the discharge channel is different,and the gas density in the area near the rod electrode recovers faster than other areas;based on the gas density recovery degree proposed in this paper,the gas density of the discharge channel recovers within 200 ms after the gap breakdown under the experimental condition.The experimental method and results in this article can provide a reference for the research of the discharge channel deionization time in the power system’s reclosing time.