长空气间隙放电过程的试验观测技术

Experimental Observation Technology for Long Air Gap Discharge

长空气间隙放电物理过程的试验观测研究是揭示长间隙放电机制和建立放电分析模型的基础。在高速光学观测技术、放电电流测量技术、空间瞬态电场测量技术和同步观测技术4方面开展了研究。通过分析高速摄影仪的成像原理,设计了针对不同放电阶段先导通道光学特性的观测方法;通过合理设计电极结构,研制全数字式光电隔离采集系统,实现了对高电位放电通道电流的全数字式测量;基于Pockels效应,研制出测量幅值上限达800 kV/m的集成光波导瞬态电场仪;基于高速摄影仪曝光时钟信号,提出了各测量设备的数据同步方案。该研究为准确地获取长空气间隙放电关键物理参数,揭示长空气间隙放电发展的物理过程提供了有力支撑。

Experimental observation technology applied to record the physical process of long air gap discharge is the key to the research of its physical mechanism and the establishment of a simulation model. High-speed optical observation technology, discharge current measurement technology, space electric field measurement technology and the method for the synchronization of the above technologies were studied in this paper. The image-forming principle of the high-speed charge coupled devices （CCD） camera was analyzed. According to the optical characteristics of the leader channel, a practical observation method was proposed. A novel electrode construction was proposed to reduce the impact of the displacement current and surface discharge current of the electrode body. A digital photoelectric isolation acquisition system was developed for the transmission of the current signal. Base on the Pockels effect, an integrated electric field measuring device with a measurement amplitude limit of 800 kV/m was developed. At last, a synchronization scheme for optical observation results and electrical measurement results using the exposure clock signal of the high-speed CCD camera was proposed. The work involved in this paper is beneficial for obtaining the key physical parameters accurately, and clarifying the physical process of long air gap discharge.