The Study of Structural Dynamic Response of Wind Turbine Blades under Different Inflow Conditions for the Novel Variable-Pitch Wind Turbine

Abstract

To ensure the safe and stable operation of small and medium-sized wind turbine generators within distributed energy systems, a new active pitch adjustment method for a 1.5 kW distributed pitch wind turbine generator is proposed in this article. The stress and displacement responses of blades under uniform inflow and extreme operating gust inflow conditions were calculated and analyzed using a two-way fluid–structure coupling method. The results showed that under the two different flow conditions, as the pitch angle increased, the stress and displacement responses of the wind turbine blades both significantly decreased, and the decrease was greater with increasing wind speed. The feasibility of the proposed variable-pitch adjustment for blade load reduction under different inflow conditions was further illustrated. The peak of the blade stress response was located at the leading-edge position in the middle of the blades (0.55R) for the different inflow conditions, while the displacement response of the blades was mainly along the waving direction. Through comparative analysis of the blade stress and displacement responses at the same wind speed under different flow conditions, it was found that the maximum mean ratio of the blade displacement and stress responses reached 1.66 and 1.67, respectively.

Keywords

• horizontal axis wind turbine
• wind speed variation
• pitch mechanism
• structural dynamics