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

Abstract

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 turned out to be closely related to temperature distribution in high altitude. In this paper, correlation between lightning hits of wind turbines and the height of -10°C layer is analyzed. When an upward lightning hits a wind turbine in winter, the height of -10°C layer was lower than 2000m in most of the cases. Moreover, winter lightning is classified into two types, namely storm type and inactive type, and it is found that parameters of lightning current observed by LLS differ depending on the type of lightning storms.