A modified method based on neutral condition for wind profile calculation under different atmospheric stability

Abstract

Wind profile plays a significant role in wind turbine design and wind resource assessment, since it reflects the vertical variation of wind speed. However, the widely used wind profile is based on the assumption that the atmosphere state keeps neutral, while the atmosphere is not static. In this paper, a modified calculation method based on neutral condition under different atmospheric stabilities has been proposed. In this way, more information about the actual wind profile can be obtained and formulated to provide with wind turbine designers and wind farm developers, etc. Firstly, the influence of atmospheric stability on wind profile has been studied. Secondly, annual and diurnal characteristics of wind profile have been presented. Taking two locations in North China and Colorado, USA respectively as examples, the performance of modified method has been verified by being compared with benchmark method- Logarithmic law. The results show that atmospheric stability has significant effects on wind profile and the proposed method has better performance to simulate to the actual wind profile. In addition, the proposed method is easy and practical.