广东野外雷电综合观测试验十年进展

雷电野外科学试验是认识雷电发生、发展物理过程及其致灾机理的重要途径,也是开展真实雷电电磁环境下雷电防护技术测试的重要方式。自2006年开始,中国气象科学研究院和广东省气象局在广州野外雷电试验基地,持续合作开展了雷电野外综合观测试验,在人工触发闪电和自然闪电物理过程及其雷电防护技术测试试验等方面取得了若干研究结果。十年期间共成功触发闪电94次,回击电流峰值最大值为42 kA,平均值为16 kA;分析给出了自然闪电预击穿过程电场变化脉冲特征类型和差异;观测发现高建筑物上行连接先导可达几百米甚至超过1 km,其发展速度可达106 m/s量级,下行先导与上行连接先导的连接呈多样性;雷电防护技术测试试验表明人工触发闪电近距离电磁场耦合在架空线路上的感应电压达到千伏量级,多回击、长连续电流和地电位抬升是造成浪涌保护器(SPD)损害的主要因素;闪电定位系统探测性能的评估结果显示粤港澳闪电定位系统的闪电和回击的探测效率分别为96%和89%,定位误差算术平均值为532 m,回击电流强度的估算值约为真实值的0.63倍。

A review of lightning observation experiments during the last ten years in Guangdong

Lightning field experiment is an important approach to understand physical processes involved in the occurrence and development of lightning as well as its disaster-causing mechanism. It is also an important way to carry out tests of lightning protection technology under real lightning electromagnetic environment. Since 2006, comprehensive lightning field observation experiments have been jointly conducted by Chinese Academy of Meteorological Sciences and Guangdong Meteorological Bureau. Research results of physical processes of artificially triggered lightning and natural lightning as well as tests of lightning protection technology are reviewed in this paper. A total of 94 flashes were successfully triggered during the ten-year period, and the maximum and average peak current of return stroke is 42 kA and 16 kA, respectively. Types and difference characteristics of electric field change pulse involved in the preliminary breakdown process of natural lightning are analyzed. It is found that the length of upward connecting leader initiated from tall structures can be several hundred meters or even more than 1 km, and its speed can reach up to the magnitude of 10⁶ m/s. Great diversity is found in the attachment of downward leader and upward connecting leader. Tests of lightning protection technology show that the voltage on the overhead lines induced by close-distance electromagnetic wave coupling from artificially triggered lightning could be up to the magnitude of kV. Multiple return strokes, continuing current and ground potential rise are the main factors that cause damages to surge protective device (SPD). Results of performance evaluation for the Lightning Location System of Guangdong-Hongkong-Macau show that the detection efficiency of flash and stroke are 96% and 89%, respectively; the arithmetic mean value of location error is 532 m; the estimated value of return stroke current intensity is about 63% of the true value.