对大气环境中脉冲电压加载下绝缘介质沿面闪络放电开展了初步放电图像诊断研究。采用超高速可见光分幅相机诊断指状电极结构下有机玻璃材料在大气环境中不同时刻闪络通道发光图像特征。实验结果表明：闪络通道形成和扩张阶段中, 阴极区域和阳极区域均产生放电发光, 放电通道沿固体电介质表面快速贯穿, 贯穿时间约15 ns, 贯穿后发光通道逐渐扩张至一定区域, 发光强度大, 维持时间长, 整体发光时间可持续到μs量级, 放电通道内能量分布有所差异。

We investigated the discharge channel optical images of surface flashover on insulator under pulsed voltage in air. The CCD camera was used to diagnose the flashover characteristics of PMMA with finger electrodes in air. The experiments show that discharges occurred in both cathode region and anode region in channel forming and expansion stage. The velocity of channel forming was fast in 15 ns. The channel region kept on expanding with high luminous intensity and the whole discharge lasted more than 1 μs. Next, we would analyse the flashover physical process in air based on the discharge channel optical images.