Development Process of Lightning Stroke on Wind Turbine Based on High-Speed Camera Observation

This paper mainly analyzes the development process of a natural upward lightning flash initiated from a wind turbine in Zhangbei wind farm in 2019 using optical data. The duration of the flash was more than 283 ms, and there are totally 7 return strokes with their peak current varied from -8.1 kA to -18.7 kA. The average 2-D speed of the leaders preceding all 7 return strokes is greater than 106 m/s, with the leader preceding RS6 being the slowest at 2.6 x 105 m/s and RS5 being the fastest at greater than 1.1 x 106 m/s. There is a significant linear positive correlation between the sum of relative luminance integral and the cut-off time of each RS, and the corresponding R2 is 0.96.