A Multivariate Nonlinear Regression-Based Method for Calculating Lightning Ablation Mass of Metal Mesh in Wind Turbine Blades

Lightning strikes have posed a severe threat to the operational safety of wind turbines. As an additional lightning-protection measure, metal meshes have been deployed on a number of turbines. However, under high-amplitude lightning currents, the mesh undergoes erosion, potentially compromising its lightning-protection effectiveness. Currently, blade-mounted meshes directly follow aerospace mesh standards, and the relationship between structural parameters and erosion mass on curved blade geometries is seldom reported. Therefore, This paper develops a parametric grid structure-based lighting strike simulation model for wind turbine blade metal mesh. The model analyzes the influence weights of mesh thickness, wire width, and grid size on the ablation mass of the metal mesh. The validity of the simulation model was verified through A+C combined lightning current ablation tests. A multivariate nonlinear regression equation for the ablation mass of the metal mesh was established, providing a quantitative method to evaluate the lightning protection capability of metal meshes with different structural parameters. The results show that under a density of 800 g/m3, the test group’s metal mesh had an ablation mass of 800 mg after exposure to the combined waveform, while the calculated ablation mass using the regression equation was 748 mg, yielding an error of 6.5%. The proposed equation provides a method to quantify the lightning protection capability of metal meshes with varying grid structural parameters.