TY - JOUR
T1 - Effective turbulence models and fatigue reliability in wind farms
AU - Sørensen, John Dalsgaard
AU - Frandsen, Sten Tronæs
AU - Tarp-Johansen, N.J.
PY - 2008
Y1 - 2008
N2 - Modeling of turbulence within wind farms with 100 or more wind turbines is important both for extreme and fatigue limit states. Behind a wind turbine a wake is formed where the mean wind speed decreases slightly and the turbulence intensity increases significantly. This increase ill turbulence intensity in wakes behind wind turbines can imply a significant reduction in the fatigue lifetime of wind turbines placed in wakes. Ill this paper the design code model ill the wind turbine code [IEC 61400-1, Wind turbine generator systems - Part 1: Safety requirements. 2005] is evaluated from a probabilistic point of view, including the importance of modeling the SN-curve by a bi-linear model. Fatigue models relevant for welded, cast steel and fiber reinforced details are considered. Further, the influence on the fatigue reliability is investigated from modeling the fatigue response by a stochastic part related to the ambient turbulence and the eigenfrequencies of the structure and a deterministic, sinusoidal part with frequency of revolution of the rotor. (C) 2008 Elsevier Ltd. All rights reserved.
AB - Modeling of turbulence within wind farms with 100 or more wind turbines is important both for extreme and fatigue limit states. Behind a wind turbine a wake is formed where the mean wind speed decreases slightly and the turbulence intensity increases significantly. This increase ill turbulence intensity in wakes behind wind turbines can imply a significant reduction in the fatigue lifetime of wind turbines placed in wakes. Ill this paper the design code model ill the wind turbine code [IEC 61400-1, Wind turbine generator systems - Part 1: Safety requirements. 2005] is evaluated from a probabilistic point of view, including the importance of modeling the SN-curve by a bi-linear model. Fatigue models relevant for welded, cast steel and fiber reinforced details are considered. Further, the influence on the fatigue reliability is investigated from modeling the fatigue response by a stochastic part related to the ambient turbulence and the eigenfrequencies of the structure and a deterministic, sinusoidal part with frequency of revolution of the rotor. (C) 2008 Elsevier Ltd. All rights reserved.
KW - Vindenergi
U2 - 10.1016/j.probengmech.2008.01.009
DO - 10.1016/j.probengmech.2008.01.009
M3 - Journal article
SN - 0266-8920
VL - 23
SP - 531
EP - 538
JO - Probabilistic Engineering Mechanics
JF - Probabilistic Engineering Mechanics
IS - 4
ER -