Experimental Evaluation of Lightning Attachment Characteristic of Two Adjacent Wind Turbines

Lightning attachment characteristic of wind turbines have been investigated by experiments with two adjacent 1:100 reduced-scale wind turbine models, simulating two 2-MW wind turbines with blades equipped with two pairs of lightning receptors. Factors including directions of downward lightning leaders relative to the two wind turbine models, and blade rotation angles, were considered. Obtained results show that receptors, especially the blade-tip receptors, have excellent protection effect on the lightning leaders from higher altitudes or from the side of wind turbines, whereas they show weaker protection effect for those from lower altitudes or from the front of wind turbines. Moreover, blade rotation angles of two wind turbines have a certain impact on lightning attachment rates, showing a tendency that the protection effect of wind turbines can be improved with the increase of relative angle difference, the elevation angle difference of uppermost blade of two adjacent wind turbines. The underlying mechanism of this tendency is also discussed. Our experimental results show significance for improving the overall lightning protection capability of multiple wind turbines in wind farms.