A Study on the Influence of Different Inflow Conditions on the Output Power and Dynamic Response Characteristics of a Variable Pitch Wind Turbine Structure

This paper introduces a novel pitch adjustment device applicable to small wind turbines. To validate its feasibility under high wind speeds and analyze the impact of pitch angle on the power output characteristics of small wind turbines, a prototype model was manufactured for wind tunnel experiments. Additionally, we conducted simulations to analyze the stress and displacement responses of key components under uniform airflow, shear airflow, and Extreme Operated Gust conditions. The numerical simulation results were compared with experimental results based on actual measurement points in the wind tunnel experiment, demonstrating that the simulation data accurately reflect the experimental test results, with an overall discrepancy of around 10%, thereby validating the accuracy of the load and constraint settings in the transient dynamics analysis. This study found that, as the pitch angle increased, the structural dynamic response of key wind turbine components under uniform airflow conditions exhibited a decreasing trend, which was proportional to wind speed. Under shear airflow conditions, the response of key components was positively correlated with the shear index, while Extreme Operated Gust significantly increased the amplitude of the response fluctuations. Furthermore, this research revealed that, with an increase in pitch angle, the maximum stress value of the gear under uniform airflow conditions decreased from 27.42 MPa to 7.64 MPa, a reduction of 72.1%. Under shear airflow conditions, the root stress of the gear decreased from 14.441 MPa to 8.879 MPa, a reduction of 49.60%. Under Extreme Operated Gust conditions, the maximum stress of the gear decreased from 17.82 MPa to 15.18 MPa, a reduction of 22.99%.