A scroll compressor includes a balancer that rotates integrally with a rotary shaft. A bushing includes a cylindrical portion and an auxiliary weight portion. The auxiliary weight portion is arranged on the outer side of the cylindrical portion. The fitting hole is provided at a position where a moment about the eccentric shaft generated by a centrifugal force acting on the movable scroll due to rotation of the rotary shaft and a moment about the eccentric shaft generated by a centrifugal force acting on the auxiliary weight portion due to rotation of the rotary shaft are in the opposite directions. As viewed in the axial direction of the rotary shaft, the center of gravity of the bushing is located on the same side of a straight line including the center of the cylindrical portion and the center of the rotary shaft as the center of the eccentric shaft.

A scroll compressor includes a balancer that rotates integrally with a rotary shaft. A bushing includes a cylindrical portion and an auxiliary weight portion. The auxiliary weight portion is arranged on the outer side of the cylindrical portion. The fitting hole is provided at a position where a moment about the eccentric shaft generated by a centrifugal force acting on the movable scroll due to rotation of the rotary shaft and a moment about the eccentric shaft generated by a centrifugal force acting on the auxiliary weight portion due to rotation of the rotary shaft are in the opposite directions. As viewed in the axial direction of the rotary shaft, the center of gravity of the bushing is located on the same side of a straight line including the center of the cylindrical portion and the center of the rotary shaft as the center of the eccentric shaft.

A detuner system for a wind turbine includes a drive train component having a natural frequency. The drive train component is configured to rotate about an axis of rotation at a range of different speeds. The detuner system includes a controller for selectively interacting with the drive train component and cause a step change in the natural frequency of the drive train component at a first threshold of the rotational speed range, and cause a step change in the natural frequency of the drive train component at a second threshold of the rotational speed range different to the first threshold.

A method for wind turbine tower damping is disclosed, as well as an associated controller and wind turbine. The method comprises determining, using one or more sensor signals, dynamic state information for a tower of a wind turbine during power production, wherein the dynamic state information comprises a tower frequency. The method further comprises determining at least one control loop gain value using the tower frequency, and generating, using the at least one control loop gain value, one or more control signals for controlling a rotational speed of a rotor of the wind turbine.

A method for compensating an imbalance of a wind rotor of a wind turbine includes applying at least one test-offset to a parameter characterizing a state of the wind rotor, wherein the imbalance depends on the parameter; measuring for the at least one test-offset an acceleration of the wind turbine, wherein the acceleration depends on the imbalance; and determining a compensation-offset based on the measured acceleration, wherein the imbalance is at least partially compensated, when the compensation-offset is applied to the parameter. Furthermore, a corresponding wind turbine includes a control unit configured to carry out the above method.

Provided is a method of monitoring the structural integrity of a supporting structure of a wind turbine, which method includes the steps of determining a fore-aft tower oscillation frequency; determining a side-to-side tower oscillation frequency; computing a working structural indicator value from the fore-aft tower oscillation frequency and the side-to-side tower oscillation frequency; comparing the working structural indicator value to a reference working structural indicator value; and issuing an alarm if the difference between the working structural indicator value and the reference structural indicator value exceeds a predefined threshold. Also provided is a system for monitoring the structural integrity of a supporting structure of a wind turbine, a wind turbine, and a computer program product for carrying out the steps of the inventive method.

The invention relates to the use of laser beams for measuring rotors, in particular wind turbines, for determining an imbalance or defining the absolute setting angle and/or measuring a half-profile of a rotor blade, and a method for determining a torsion of the rotor blade as a deviation between two pitch angles. The invention enables the determining of the absolute pitch angle of a rotor blade during operation, without it being necessary to obtain information relating to the rotor blade or reference points with a known position relative to the pitch axis, in particular using measuring devices that are mobile and/or positioned on the ground. It is also possible to contactlessly detect imbalances.

The present invention relates to a rotor control system for actuating pitch of pitch adjustable rotor blades of a wind turbine in order to reduce edgewise blade vibrations. The system comprises a pitch actuation unit being arranged to receive an edgewise load signal and apply m-blade coordinate transformations, such as the Coleman transformations, to the edgewise load signal. Based on a selected signal component at either a backward whirling frequency or a forward whirling frequency, a modified modification signal is obtained.

A method for wind turbine tower damping is disclosed, as well as an associated controller and wind turbine. The method comprises generating, using at least a first sensor signal, a first pitch reference signal for one or more rotor blades of a wind turbine during partial load operation. The method further comprises determining, using at least a second sensor signal, dynamic state information for a tower of the wind turbine. The method further comprises generating a second pitch reference signal by adapting the first pitch reference signal using the dynamic state information. The method further comprises selecting a maximum pitch reference signal from the second pitch reference signal and a saturation pitch reference signal. The method further comprises communicating the maximum pitch reference signal to control a pitch of the one or more rotor blades.

A detuner system for a wind turbine includes a drive train component having a natural frequency. The drive train component is configured to rotate about an axis of rotation at a range of different speeds. The detuner system includes a controller for selectively interacting with the drive train component and cause a step change in the natural frequency of the drive train component at first threshold of the rotational speed range, and cause a step change in the natural frequency of the drive train component at a second threshold of the rotational speed range different to the first threshold.