Wind Energy

158 A. Rauh et al.
0.2
0.1
−0.1
g
10 20 30 40 50
Fig. 27.4. Response function g(t) for the 150 KW turbine Vestas V25 in Beit-Yatir
for mean wind speed Ū =8ms−1 , derived in ref. [1] from data of ref. [3]. Time t
and g are in units of seconds and reciprocal meter, respectively
problem that, at the Tjareborg site, wind speed is measured relatively far away
from the turbine, at a distance of 120 m, which poses the question whether
the relevant wind fluctuations acting in the rotor plane are still sufficiently
correlated with the wind-speed fluctuations measured far away, especially in
view of the response times of the order of a couple of seconds.
In conclusion we have shown, that an empirical power curve can be
extracted from high-frequency measurements of only one day. Second, we
demonstrated that for a proper power output prediction effects of delayed
response have to be considered.
References
1. A. Rauh and J. Peinke, A phenomenological model for the dynamic response of
wind turbines to turbulent wind, J. Wind Eng. Ind. Aerodyn. 92(2003), 159–183
2. E. Anahua, F. Böttcher, S. Barth, J. Peinke, M. Lange, Stochastic Analysis
of the Power Output for a Wind Turbine, Proceedings of the European Wind
Energy Conference-EWEC in London 2004, as CD
3. A. Rosen and Y. Sheinman, The average power output of a wind turbine in
turbulent wind, J. Wind Eng. Ind. Aerodyn. 51(1994), 287–302
4. The Tjareborg Wind Turbine Data (1988–1992). Database on Wind Characteristic,
http://www.winddata.com, Technical University of Denmark (DTU),
Denmark, 2003
t