In order to repair the transmission line which was cut off by lightning as soon as possible, it is necessary to determine the location of lightning strike quickly and accurately. The detection efficiency of wide area lightning monitoring system is about 90% and its positioning error is about 800m. It can meet the operation and maintenance requirements of transmission lines. However, for distribution network lines, its positioning accuracy is insufficient. Therefore, based on frequency domain constant false alarm rate (CFAR) detection method and wavelet analysis method, an efficient detection method for lightning impulse signal is proposed in this paper. It improves the recognition and monitoring accuracy of lightning impulse signal. A lightning monitoring device for distribution network is designed, which uses multi-channel lightning signals to locate and analyze. The device has been applied in Datong to monitor lightning activities.

The results show that the lightning monitoring system developed in this paper is more accurate in positioning. Based on the results of lightning monitoring, the influence of topography on lightning activity is analyzed.