A study on observation results of lightning phenomena on distribution lines based on a lightning-surge analysis model for direct lightning strokes

In order to rationalize the lightning protection design of distribution lines, lightning phenomena on TEPCO's distribution lines has been continuously observed. The observation has been carried out with still cameras and monitoring sensors of lightning surges. The result clears the features of lightning performance of distribution lines. For example, direct lightning strokes are the major cause of present distribution line faults. This fact suggests that it is important to investigate observation data of a direct lightning stroke. In this study, the paper analyzed the observation data based on a direct lightning analysis model. The calculated waveforms were compared with the measured waveforms of the observation in distribution lines. Moreover, probability distributions of surge current and voltage were calculated with the Monte Carlo method. These results provided new data on lightning performance.