Scaled experiment and observation of the lightning discharge process of rotating wind turbines under different shapes of high-voltage electrodes in the laboratory

Abstract

In this study, a discharge test for scaled wind turbine is performed to examine the lightning discharge characteristics of rotating wind turbines, and an observation platform is designed. Moreover, the wind turbines are subjected to discharge simulation with rod and arc electrodes, and high-speed and single-lens reflex cameras are used to observe the physical discharge process. Under the rod electrode, the downward leader is initiated first, and its length occupies a larger proportion of the discharge gap. The discharge contains multiple stepped leaders. When the gap distance is less than 4 m, the probability of occurrence of negative stepped leaders may be smaller. As the gap distance increases, the number of stepped leaders increases significantly. Under the arc electrode, the upward leader is initiated first, and its length accounts for a larger proportion of the discharge gap. With the rotation of the wind turbine, the upward leader is initiated earlier and the length is longer. Furthermore, the speed of its development does not differ significantly. The discharge simulation process under the arc electrode is similar to natural lightning strikes on wind turbines.