Spectral coherence model for power fluctuations in a wind farm

This paper provides a model for the coherence between wind speeds located in a horizontal plane corresponding to hub height of wind turbines in a large wind farm.The model has been developed using wind speed and power measurements from the 72 Wind Turbines and two of the meteorological masts from Nysted offshore wind farm during 9 months.The coherence model developed in this paper is intended for use of power fluctuations in large offshore wind farms. In this way, analysing the current coherence models it is shown the needing of a new one, adapted to the characteristic distances and the related time scale.

► Nine months of wind speed data in a large offshore wind farm are analysed.
► Current spectral coherence models are not suitable for power fluctuation studies.
► Influence of distance, average wind speed or inflow angle are evaluated.
► Spectral coherence models between wind speeds in a horizontal plane are proposed.