Development of Paint Coatings for Lightning Protection on Wind Turbine Blades

Abstract

As wind power generation increases and wind turbines become larger, the number of lightning strikes on wind turbines increases, and damage to blades in particular causes significant losses. Now, the main lightning protection method for blades is a receptor, which is a conductor attached to the tip of the blade to capture lightning, but there have been cases where lightning is not captured and strikes outside the receptor. Therefore, there is an urgent need for a method that can guide the lightning current to the receptor without damage when lightning strikes outside the receptor, and we are focusing on paint coatings in this study. Coatings are classified into two types according to the conductivity of their surface, and each type has a different protection system. The conductive coating enables protection by mitigating the electric field concentration and quickly completing the formation of a discharge path inside the coating. On the other hand, the nonconductive coating enables protection by accelerating the propagation of surface streamers, which is the precursor to the formation of a creeping discharge path. Considering environmental load, the nonconductive coating is suitable for actual applications.