No. 1147
	Lightning striking characteristics to structures
	Investigation Committee on lightning striking characteristics to structures
	Keyword : Lightning discharges, Lightning strokes, Lightning shielding, Electro-geometric model, Striking distance
	Recently, anomalous lightning strikes to the high voltage transmission lines in mountain area have been reported. This suggests that practical lightning shielding model (Electro-geometric Model) which has been widely used, could not be applied to the structures of more than 100m in height. Furthermore the number of the lightning strikes to the wind turbine blades increases with the increase of wind power plants and it is a serious problems for the wind power plants. Nevertheless, the lightning striking characteristics to the non-metallic structures have not been fully understood yet. In these backgrounds, the investigation committee on lightning striking characteristics to structures has studied lightning discharge characteristics to many kinds of structures including the non-metallic structures and the lightning shielding models. This report summarizes the studies carried out by the committee. In the first half, the report deals with the lightning discharge characteristics to many kinds of structures; for example transmission lines, distribution lines and wind power plants and so on.,. In the second half, the report deals with the lightning shielding models proposed so far. These models can be classified into two categories as the engineering model and the physical model. The report shows both types of models and reviews the recent status of the models. Finally, researches on lightning strikes to structures that should be made in future are discussed.
	©2007. The Institute of Electrical Engineers of Japan