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SUMMARY In recent years, frequent damage to wind turbines by winter lightning has been reported in the region along the Sea of Japan. It is a serious finding that lightning hits concentrate on wind turbines in this region. The authors investigated the increase rate of the frequency of lightning hits on wind turbines due to wind turbine construction by using LLS (lightning location system) data. As a result, an experimental formula to estimate the increase rate of the frequency of lightning hits on wind turbines as a function of parameters related to the construction conditions, namely the height of wind turbines, the height above sea level, and the latitude, is proposed. [ABSTRACT FROM AUTHOR]

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 °C layer is analyzed. When an upward lightning hits a wind turbine in winter, the height of the-10 °C 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. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 184(2): 44-50, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22357 [ABSTRACT FROM AUTHOR]

Lightning electric-field waveforms related to power line faults in winter have been identified. Most of those waveforms appear to be associated with upward lightning discharges with absolute peak currents of over 100 kA. They are quite different from common return-stroke waveforms, and the lightning discharges which produce these characteristic waveforms are called GC (Ground to Cloud) flashes. These high-current lightning discharges are distributed around the coastline in different ways depending on their polarities. The spatial distributions of high-current lightning discharges around Japan are also investigated. It is revealed that the region of Honshu Island along the coastline of the Sea of Japan belongs to the area in which the density of high-current lightning flashes is the highest in Japan through the year. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 170(1): 8–15, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20874 [ABSTRACT FROM AUTHOR]

In this paper, lightning electric field waveforms related to notable power transmission-line faults in winter along the coastline of the Sea of Japan were examined. Most of the wave- forms of the observed electromagnetic field changes, which were more than five times as intense as an average negative return- stroke fields, are inferred to be associated with upward lightning discharges. Lightning discharges that produce such characteristic waveforms are termed ground-to-cloud flashes, and properties of the associated electric field waveforms are examined. These lightning discharges in winter distribute around the coastline of the Sea of Japan in different ways depending on their polarities. [ABSTRACT FROM AUTHOR]