棒-棒间隙操作冲击放电过程的试验观测

Experimental Study on the Discharge Processes of Rod-rod Air Gap Under Switching Impulse Voltage

为揭示操作冲击作用下的棒-棒间隙放电过程,采用CCD高速摄影仪开展了2～10.5m间隙尺度正极性及1～4.5m间隙尺度负极性棒-棒间隙放电观测试验,根据观测结果总结了正、负极性棒-棒间隙放电发展过程,并获取了放电发展过程中跃变尺度、放电发展速度等特征参数随间隙尺度以及放电发展过程的变化规律。在正极性棒-棒间隙击穿过程中,正极性下行先导起主导作用;在负极性棒-棒间隙击穿过程中,梯级发展的负极性下行先导起主导作用;随着放电间隙尺度的增加,起主导作用的放电过程发展尺度占间隙的比例逐渐增加;跃变阶段的正、负极性先导发展速度均随先导的伸长而逐渐增加;负极性棒-棒间隙放电的跃变阶段可观测到空间先导的发展过程。试验观测研究进一步揭示了棒-棒间隙放电发展过程,可为棒-棒间隙放电物理过程研究提供参考。

In order to further reveal the discharge process of rod-rod air gap under switching impulse voltage,by means of two CCD high-speed cameras,discharge experiments with the gap scale of 2～10.5m for positive and 1～4.5m for negative were carried out.The discharge processes under positive or negative switching impulse voltage were proposed,and the variation laws of discharge characteristics,such as scale of final jump,leader development velocity,with gap scales were summarized.In positive rod-rod discharges,the positive continuous downward leader guides the discharge process.However,in negative rod-rod discharges,the negative downward stepped leader guides the discharge process.The effects of the guiding processes are more remarkable as the the gap scale increases.At the final jump stage,velocities of leaders increase with their elongations.Moreover,space leaders were observed at the final jump stage of negative discharges.The results clearly reveal the discharge process of rodrod air gap,and are benefit for studying the discharge mechanisms of the rod-rod discharges.