Calculation Method of Instantaneous Wind Speed Spatial Distribution of Wind Farm

Abstract

Instantaneous wind speed spatial distribution of wind farm is the basis of the optimal control for wind turbines. A calculation method was proposed for the instantaneous wind speed spatial distribution in wind farm, which made the instantaneous wind speed spatial distribution is divided into wake and non-wake zone. For the non-wake zone, the instantaneous wind speed spatial distribution is mainly affected by the flow field coupling between wind turbines, in order to describe the influence accurately, a cross spectral matrix was constructed including the wind turbine mutual distance and the azimuth in wind farm, and the solving calculation process of the cross spectral matrix was deduced. For the wake zone, single wind turbine wake model and wake superposition model were established according to conservation of momentum, and then the average wind speed spatial distribution in wake zone was calculated. According to the average wind speed spatial distribution, the instantaneous wind speed spatial distribution was calculated. A wind farm is selected as case to verify the calculation method, and the results show that this calculation method can accurately describe the instantaneous wind speed spatial distribution of wind farm.