Abstract: In response to the current issue of the independent design of the topology structure and internal layer parameters of large-scale wind turbine blades, which hinders the maximum reduction of blade weight, this paper proposes a hierarchical optimization strategy for the design of wind turbine blade structure topology and layer parameters. Taking a 5 MW wind turbine blade as the optimization target and considering 7 extreme load cases, the blade’s topology structure is optimized based on the density method. The results of the first-level optimization show that the blade possesses characteristics such as asymmetric main beams and offset webs. Subsequently, treating the topology structure parameters and material layer parameters as second-level optimization variables, with the minimization of blade weight as the optimization objective and the Tsai-Wu’s failure factor, blade tip displacement, and natural frequency as constraints, a particle swarm algorithm is employed to jointly optimize the blade’s topology structure and layer parameters. The results indicate that, compared to the reference blade and while satisfying the blade’s structural strength and deformation requirements, the blade weight is reduced by 12.1% and the blade tip displacement is reduced by 9.5%. This study holds significant reference value for the lightweight design of wind turbine blades.

Key words: wind turbine blades, topology structure, hierarchical optimization, extreme load, layer parame-ters, composites