Case Study of "Wake Effect" of Adjacent Offshore Wind Farms

Abstract

[Introduction] The purpose of this paper is to study the influence of real "wake effect" of adjacent offshore wind farms on generation loss. [Method] The method is established with the wake scene classification based on the actual arrangement of wind farms under different wind direction and the real wake power loss of adjacent wind farms (with a spacing of more than 20D) in operation are analyzed, based on the actual SCADA data of wind turbines in large offshore wind farms and the measured wind data of LIDAR in the same period. [Result] The results show that: for the large-scale offshore wind farms with regular arrangement, the power generation normalization of the actual SCADA data can better reflect the distribution characteristics of offshore wind energy resources and the difference of power generation capacity; Under the condition of highly centralized wind direction, the adjacent wind farms in the downwind are obviously affected by the "wake effect" of the upwind wind farm; The buffer zones with different distances of adjacent wind farms have an obvious effect on the recovery of wind speed which affected the power generating capacity. The power generating capacity can be improved but if the buffer zone can reach enough distance; In different scenes of this case, the buffer zone distance is between 23D and 44D, and the power loss of wake decreases by 27%~4%. [Conclusion] This work can provide guidance for the planning of offshore wind power base and the optimization design of large offshore wind frams.

Keywords

• adjacent wind farms
• wake effect
• power generation normalization
• buffer zone
• layout optimization