The effect of yaw speed and delay time on power generation and stress of a wind turbine

Abstract

ABSTRACT Through the self-researched and manufactured dynamic rotating platform and model wind turbine, experiments were carried out at the open end of the wind tunnel, and the wind direction angle change and the yaw versus wind process were simulated. The influence of two variables (yaw speed and yaw delay time) on wind turbine power and blade stress is studied. The results are: During the dynamic yaw process, blade stress decreases from the root to the tip. Among the 4 yaw speeds (0.5°/s, 1.0°/s, 1.5°/s, 2.0°/s), the stress and power increase the fastest at 0.5°/s yaw speed, and the slowest increase at 2.0°/s. The rate of increase is inversely proportional to the yaw speed. It is found that in the dynamic yaw process, the yaw angle range of 20° to 0° is the main area of stress increase and power increase. In addition, the yaw delay time is investigated. It is found that if there is a delay time of 30S, when the yaw angle is 30°, the stress value decreases by 0.73711MPa, when the yaw angle is 60°, it decreases by 0.02965MPa, and when the yaw angle is 90°, it decreases by 0.0065MPa. It can be known that as the yaw angle increases, the effect of the delay time gradually decreases, so the delay time can be controlled in stages, that is, when the yaw angle is larger, a smaller delay time is used. We also introduce a dimensionless coefficient, which represents the ratio of power to blade stress. It is pointed out that a yaw speed of 0.5°/s is used at a yaw angle of 30°, a yaw speed of 1.0°/s at 60°, and a yaw speed of 2.0°/s at 90°. The results show that the staged control of the yaw speed can avoid power loss and improve the reliability of the wind turbine during operation.