Direct Lightning Hits on Wind Turbines in Winter Season Lightning Observation Results for Wind Turbines at Nikaho Wind Park in Winter

Lightning observation has been carried out at the Nikaho wind park since 2003 by CRIEPI and J-Power using still cameras and specially designed Rogowski coils of wide frequency band from 0.1 Hz to 100 kHz. In 2005, 125 lightning flashes on wind turbines were observed and 85 lightning current records on wind turbines were obtained. The 50% value of lightning current peak is about 3.1 kA and the 50% value of charge amount of pulse-type current and continuing-type current are 0.13 C (18 data) and 33.8 C (67 data), respectively.