地闪回击电流测量综述

Overview of Measurements on Cloud-to-Groud Flash Return Stroke Currents

地闪回击电流是雷电的一个重要特征参数。其测量数据的积累对于雷电防护技术的提高具有重要意义。目前国内外的雷电研究人员通过矮塔、高塔直接观测,人工引雷观测和电场电流关系反衍的方法对地闪回击电流进行了大量的观测研究,并取得了丰富的观测资料。观测表明,负地闪首次回击电流平均为30kA,继后回击电流平均12kA。正地闪回击电流平均为35kA,有时可达几百kA。不同地区地闪回击电流平均值略有不同。高塔测量是主要的雷电流参量直接测量方法,但不同高度测量的地闪回击电流无论峰值还是波形都存在一定的差异。人工引发闪电和自然闪电继后回击雷电流的测量结果较为一致。间接估测雷电流参数的方法随着地闪回击模式的发展将成为主要的方法之一。

The current in Cloud-to-Groud （CG） flash return strokes is an important feature of lightning. It＇s important for improving the technology of lightning protection. Nowadays more and more data are obtained by many observing methods, including short towers, tall towers, triggered-lightning and far field-current relations. It indicates that the mean of negative first return stroke currents is 30kA, the mean of negative subsequent return stroke currents is 12kA. And the mean of positive first return stroke currents is 35kA, the value ot that sometimes can be hundreds. There are some differences for the mean of return stroke currents in different regions. Measurement using short towers or tall towers is the dominating method for the direct measurement of lightning currents. Both peak values and wave shapes are different at different height. The measurements of the subsequent return stroke current for nature-lightning and triggered-lightning are similar. The indirect estimation is more and more important with the development of lightning return strokes models.