A vibration absorber which, in addition to a main mass which is fixed thereto and moved along a curved trajectory by a driving mechanism, comprises a substantially smaller variably adjustable rotating flywheel mass which is moved together with the main mass along the trajectory thereof, enabling the adjustment of the frequency of the absorber. The rotating flywheel mass is driven by a novel belt device independently of the driving mechanism. A rotating vibration absorber which, along with the main mass and the rotating flywheel mass, comprises its own damping unit, such as an eddy-current damping unit.

An apparatus for dampening of acoustic noise generated by air-cooling of at least one turbine component provided with the nacelle of a wind turbine is provided. Apparatus for dampening of acoustic noise generated by air-cooling of at least one wind turbine component provided with the nacelle of a wind turbine, comprising at least one acoustic dampener, with the acoustic dampener including at least one acoustic dampening channel structure having at least one acoustic dampening channel connected with at least one inlet opening of the acoustic dampening channel structure and at least one outlet opening of the acoustic dampening channel structure.

The present invention relates to a damper module adapted to be secured to a wind turbine tower section, the damper module comprising at least one liquid damper secured to a frame structure, wherein each liquid damper comprises a container comprising an interior volume containing an amount of liquid, wherein the amount of liquid in the interior volume of the container sets a natural frequency of the liquid damper, and wherein the frame structure comprises an interface arrangement configured for, in cooperation with a damper module suspension arrangement in a tower section, securing the damper module to said tower section, and a liquid damper fastening arrangement configured for securing said at least one liquid damper to the frame structure. The present invention further relates to a liquid damper and a tower section having at least one damper module secured thereto.

The present disclosure is directed to a system and method for reducing audible tonality of a wind turbine caused by vibrations generated by the drivetrain assembly thereof. The system includes a plurality of damping elements mounted at a plurality of locations on an inner surface of a tower of the wind turbine, the plurality of locations having vibration levels above a predetermined threshold. Thus, during operation of the wind turbine, the plurality of damping elements are configured to damp vibrations of the tower so noise generated thereby.

The present invention provides a floating offshore wind turbine capable of suppressing yawing of a nacelle caused by a gyro effect which is a cause of adverse influence of power generating efficiency of a wind turbine and endurance of devices thereof. The floating offshore wind turbine 10 includes a rotor 11 which is rotated by wind, a nacelle 13 in which a rotation shaft 12 of the rotor 11 is accommodated, and a tower 15 including a turning seated bearing 14 which supports the nacelle 13 such that the nacelle 13 can turn with respect to a sea surface P to exert a weathercock effect. The tower is provided with yawing suppressing means 16 which suppresses yawing T of the nacelle 13. According to this, it is possible to suppress the yawing T of the nacelle 13 generated by a gyro effect caused by yawing Ω generated in the floating body 31 by waves of the sea surface P.

Provided is a wind turbine including a tower, a nacelle arranged at an upper end of the tower, a hub connected to the nacelle and a plurality of blades extending from the hub, wherein the wind turbine further includes a drag device for increasing the drag of the wind turbine) in air and/or for increasing the aerodynamic damping, the drag device including a planar surface configured to be directed perpendicular to an air flow.

The invention relates to a method for wind turbine generators for reducing electrical disturbances in the form of power variations which are caused by damping controllers arranged the compensate structural oscillations by inducing shaft torque variations. The shaft torque variations are generated by imposing corresponding variations in a generator set-point, e.g. a power or torque set-point. Variations in the generator set-point cause undesired variations in the power injected to the grid by one or more wind turbine generators. According to an embodiment of the invention the electrical disturbances may be reduced by limiting a damping controller's control action. The amount of limitation or restriction of the damping controller may be determined on basis on electrical disturbance information determined from power measured e.g. at a location on the grid.

A method for damping vibration in a wind turbine including aerodynamic devices for influencing the airflow flowing from the leading edge of a rotor blade of the wind turbine to the trailing edge of the rotor blade, each aerodynamic device being movable by an actuator between a first protruded configuration and a second retracted configuration is provided. The method includes measuring vibrations in the wind turbine, if the measured vibrations are greater than a threshold within a predefined frequency band, moving a portion of the aerodynamic devices to the second retracted configuration and continuing to measure vibrations, if the measured vibrations are still greater than a threshold within a frequency band, reducing the pitch angle interval of the blade and continuing to measure vibrations, if the measured vibrations are still greater than a threshold within a frequency band, moving all the aerodynamic devices to the second retracted configuration.

A method is provided for dampening oscillations in a wind turbine, the wind turbine having a tower 1, a rotor 3 arranged on the tower 1 such as to be able to rotate about an X axis, and a plurality of blades 4 with adjustable pitch mounted on the rotor. The method includes monitoring the fore-aft oscillation of the tower 1 in the direction of the X axis, at the 2nd or a higher bending mode frequency; determining a compensating torque to be applied by the rotor 3 to the tower 1 of the wind turbine about a Y axis, which is horizontal and at right angles to the X axis, for at least partly dampening the oscillation at the 2nd or higher bending mode frequency; determining for each rotor blade 4 of the wind turbine an adjustment of the pitch angle suitable to generate the compensating torque about the Y axis; and adjusting the pitch angle β1, β2, β3 of at least one of the individual blades 4 to generate at least part of the compensating torque.

A wind-power-installation tower segment, a wind-power-installation tower, a wind power installation, a use of a holding arrangement, a use of a first transport device and of a second transport device, and to methods for assembling a wind-power-installation tower segment and for assembling a wind-power-installation tower section. In particular, a wind-power-installation tower segment for a wind-power-installation tower, comprising a shell segment, having an extent in the direction of a segment height, a segment ring direction and a segment thickness, and an upper horizontal abutment side and a lower horizontal abutment side, a holding device for arranging requisites inside a wind-power-installation tower segment, having a main section, and at least one projecting section, wherein the main section and the at least one projecting section are arranged adjacently to each other in the segment ring direction, wherein the main section and the at least one projecting section enclose a holding-device angle, a coupling device, which is arranged in a coupling section of the shell segment, adjoining the upper horizontal abutment side, wherein the holding device is coupled to the shell segment by means of the coupling device.