As the size of the wind turbine tower becomes larger and larger, research on assembled wind turbine tower that is advantageous for transportation and installation is continuing. Large wind turbine tower require door openings for maintenance. The opening of the tower has an irregular cross section, and an excessive stress is generated due to the door opening. The result is structural damage to the tower and many accidents. In this research, stress analysis was performed on a model with internal stiffener to prevent excessive stress. The stress was investigated around the openings where the tower was resonant and excessive stressed, and the shape of the openings was optimized. Through optimization, we confirmed that the maximum stress was reduced by about 6% with respect to the initial value.

The object of research is based on 1.5 MW wind turbine blade. This paper has carried out the aerodynamic shape optimization design of wind turbine blade. Based on the aerodynamic basic theory of wind turbine blade design and combined with particle swarm optimization algorithm(PSO), the design optimization model of the aerodynamic shape of blade is established. Through this study, the optimization results of the angle inducing ′ and tangential inducing  were obtained. The calculation programs are written and calculated chord length and torsion angle of the blade used by ′ and . The calculation result for the optimized wind turbine was 1.38 MW when the wind speed was 16 m/s. The 8 % error could be considered as an engineering acceptable error and the calculated values can be proved the correctness of the design value.