Characteristics of Winter Lightning Threatening Wind Turbines in Coastal Area of the Sea of Japan

摘要

Wind turbines on the coast of the Sea of Japan have been damaged by lightning in winter. This is due to the frequent occurrence of upward lightning from wind turbines in winter. Occurrence of upward lightning proves to be closely related to the temperature distribution at high altitudes. In this paper, the correlation between lightning hits of wind turbines and the height of the -10℃ layer is analyzed. When an upward lightning hits a wind turbine in winter, the height of the -10℃ layer is lower than 2000 m in most cases. Moreover, winter lightning is classified into two types, namely, the storm type and the inactive type, and it is found that the parameters of lightning currents observed by LLS differ depending on the type of lightning storm.