Study on offshore wind profile based on neutral equivalent wind speed

Abstract

To address the issue of extrapolation inaccuracy when the hub height of offshore wind turbines exceeds the measurement height of meteorological masts, this study proposes an offshore wind profile model based on neutral equivalent wind speed by comprehensively considering the Monin-Obukhov similarity theory and sea surface dynamic roughness. First, the effects of wind shear exponent, atmospheric stability, and turbulence intensity on offshore wind resources were investigated. Then, the proposed model was validated using measurement data from an offshore meteorological mast in Dalian. Compared with traditional extrapolation methods, the model yields annual average wind speed and wind power density at hub height that are closer to measured values, with root mean square error and mean absolute error of wind speed being 0.43 m/s and 0.28 m/s respectively. Moreover, the model effectively reflects the influence of sea surface dynamic roughness and atmospheric stability variations on vertical wind speed distribution, overcoming the limitations of conventional wind shear power law. This provides a scientific basis for offshore wind resource assessment and preliminary planning of wind farms