Patent ID: 6695588
Filing Date: 2004-02-24
Classification: F03D,F05B,Y02E,Y10S

Abstract:
A wind turbine comprisinga stationary part including a tower extending substantially vertically and a foundation to which a lower end part of the tower is fixed, a nacelle comprising a wind rotor having at least one blade arranged on a main shaft having a substantially horizontal rotation axis and a power transmission system, a yawing system comprising a stationary part being fixed to an upper end part of the tower and a movable part being fixed to the nacelle, the stationary part and the movable part being designed so that the nacelle is being supported vertically and horizontally by the tower and may pivot relatively to the tower about a substantially vertical yawing axis, and oscillation damping means provided at the top of the tower and/or in the nacelle and/or distributed on the outside of the tower/nacelle and comprising at least one container being partly filled with a liquid, the primary damping frequency of the oscillation damping means being designed for damping oscillations of the first natural bending frequency of the wind turbine with a substantially unidirectional damping of a magnitude being equivalent to a logarithmic decrement of oscillations of said first natural frequency of the wind turbine of at least 2%, and the total mass of the liquid contained within the at least one container being equal to at least 0.6% of the mass of the nacelle.