Full-scale measurements at the Dutch experimental wind farm at Sexbierum. Draft final technical report
report
Between 1991 and 1993 detailed measuring campaigns have been carried out in the Dutch Experimental Wind Farm in order to collect experimental data on the power output, the wind and turbulence structure in the wind farm and the dynamic loads experienced by a wind turbine inside the wind farm. To this end the following quantities have been monitored — fast rate wind speed data in wakes; — wind turbine power; — fatigue loads in various components, such as blades, hub and shaft. The lay-out ofthe Dutch Experimental Wind Farm is described. Instrumentation and measuring campaigns are described in detail. Measurement ofthe wind farm power output shows that the wake losses in the wind farm are approximately 4%. Apparently the losses are limited due to the orientation ofthe wind farm with respect to the prevailing wind. The measurements indicate that the power output ofthe individual wind turbines drops offsharply in the second and third row and gradually increase again going to the turbines further downstream. Two campaigns are described covering measurements ofthe wake properties behind a single turbine and behind turbines in line. The single wake campaign contains measurements at 2.5, 5.5 and 8 rotor diameters downstream. The double wake campaign (with the turbines at 5 rotor diameters inter-distance) describes measurements at 4 rotor diameters downstream the second turbine. The analyses described comprise the u-, v-, and w-components of the wind speed, of the turbulence intensity and of the shear stresses in the wake.
Topics
TNO Identifier
253408
Publisher
TNO
Collation
85 p.
Place of publication
Apeldoorn