Patent ID: 6672837
Filing Date: 2004-01-06
Classification: F03D,F05B,F16F,Y02E,Y10S

Abstract:
A wind turbine comprising:a foundation, a tower extending substantially vertically and being mounted at a lower end on the foundation, a nacelle supported by an upper end of the tower, a wind rotor having at least one blade arranged on a main shaft having a substantially horizontal rotation axis and being arranged at the nacelle with the wind rotor extending from one end of the nacelle, the at least one blade defining a rotational plane being perpendicular to the rotation axis, and oscillation damping means provided at the nacelle and being designed for damping oscillations of the at least one blade in the rotational plane of the at least one blade, wherein the oscillation damping means are designed for damping oscillations of at least at one of a lower frequency and an upper frequency, wherein; (a) if the lower frequency oscillations are dampened, the lower frequency is substantially equal to the first eigenfreguency in the rotational plane of the at least one blade minus a frequency of rotation of the rotor, or (b) if the upper frequency oscillations are dampened, the upper frequency is substantially equal to the first eigenfrequency in the rotational plane of the at least one blade plus the frequency of rotation of the rotor.