Damping of oscillations of the first bending mode of a wind turbine is
performed means of one or more containers partly filled with a liquid for
damping oscillations of the first natural bending frequency of the wind
turbine. The damping means comprises a plurality of box shaped containers
having a square cross section and being partly filled with liquid so as to
provide a unidirectional damping with a logarithmic decrement of
oscillations of the first natural bending frequency of the wind turbine of
at least 4-8%. For off-shore wind turbines, the combined excitation of the
wind and sea waves requires more damping, the damping is preferably
equivalent to a logarithmic decrement of 10-15%. Furthermore, the
invention relates to damping of oscillation of the second bending mode of
a wind turbine and to the combined damping of oscillations of the first as
well as the second bending mode of the wind turbine.
