A method for decoupling a mechanical drivetrain resonance mode of an inverter-based resource from the external electrical system includes receiving one or more voltage feedback signals at a node between the inverter-based resource and the external electrical system. The method also includes filtering the one or more voltage feedback signals to extract changes in a voltage at a frequency associated with the drivetrain resonance mode. Further, the method includes determining at least one current command or power command based on the filtered one or more voltage feedback signals. Moreover, the method includes controlling the power converter according to the at least one current command and controlling the energy buffer according to the power command so as to reduce or eliminate the changes in the voltage at the frequency associated with the drivetrain resonance mode.

A method of damping motion of a wind turbine, the wind turbine comprising a rotor and a floating platform. A motion signal is generated which is indicative of a motion of the wind turbine. A wind direction signal is generated which is indicative of a wind direction relative to the floating platform. A damping signal is generated on the basis of the motion signal and the wind direction signal, and the motion of the wind turbine is damped on the basis of the damping signal, for instance by adjusting the pitch of the rotor blades. A phase of the damping signal may be controlled on the basis of the wind direction signal.

A method for damping drivetrain vibrations of a wind turbine. The drivetrain has, at least, a rotor and a generator. The method includes receiving a first rotational speed signal at a first location along the drivetrain, the first rotational speed signal being a proxy for rotor speed of the rotor. The method also includes receiving a second rotational speed signal at a second location along the drivetrain, the second location being downwind from the first location, the second rotational speed signal being a proxy for generator speed of the generator. Further, the method includes determining a speed error based on a comparison of the first and second rotational speed signals. Moreover, the method includes determining a torque deviation signal for the wind turbine configured to dampen the drivetrain vibrations when the speed error exceeds a first speed threshold. In addition, the method includes applying the torque deviation signal to the generator to dampen the drivetrain vibrations.

A method for controlling operation of a generator for a wind turbine is disclosed. At least one amplitude of a harmonic in the gearbox vibrations is determined. A torque modulating signal for the generator is generated. A phase angle and the amplitude are adjusted during operation of the generator, until a minimum in amplitude of a resultant vibration is reached, thereby obtaining an adjusted torque modulating signal. The adjusted torque modulating signal is injected into the generator, resulting in the resultant vibration of vibrations of the gearbox and vibrations of the generator, corresponding to the harmonic in the gearbox vibrations, being reduced.

A method for controlling a wind turbine is disclosed. The wind turbine comprises three or more wind turbine blades, and blade connecting wires, each blade connecting wire extending between a connection point on one wind turbine blade and a connection point on a neighbouring wind turbine blade. The wind turbine further comprises pre-tension wires, each pre-tension wire being connected to one of the blade connecting wires and to a pre-tension adjustment mechanism . The method comprises measuring at least one parameter of the wind turbine, and deriving an estimate for a rotor imbalance of the wind turbine from the at least one measured parameter. The pre-tension adjustment mechanism is controlled based on the estimated rotor imbalance in order to counteract the rotor imbalance.

A method is provided for controlling power oscillations at a point of common coupling in a wind park. Individual power reference offsets defining an adjustment to a wind turbine power reference signal for counteracting mechanical oscillations in the respective wind turbines are received from respective wind turbine controllers. Based on an aggregated power reference offset, a total power oscillation compensation signal is determined. Individual power oscillation compensation signals for adjusting the wind turbine power reference signal of respective wind turbines are determined based on the individual power reference offsets and the total power oscillation compensation signal. These individual power oscillation compensation signals are then sent to the respective wind turbines.

A method is for controlling a wind turbine. The wind turbine has a tower, a nacelle, a rotor with at least two rotor blades and a yaw system with at least one yaw drive configured to rotate the nacelle about a vertical axis of the tower (yaw axis). A control signal for the at least one yaw drive depends on at least one signal indicative of the wind direction. The control signal for the at least one yaw drive further depends on at least one value indicative of a vibration mode of the rotor blades.

A damping arrangement for a wind turbine is provided. The damping arrangement (20) comprises a base (24) affixable to a surface (40) of the wind turbine (2); and a magnet 5 arrangement. The magnet arrangement comprises a first magnet (38) and a second magnet (54). The first magnet (38) is fixed relative to the base (24) and is arranged to generate a first magnetic field. The second magnet (54) is supported by the base (24) to be spaced from the first magnet (38) when the base (24) is fixed to the surface (40), and is arranged to generate a second magnetic field that interacts with the first magnetic field 10 to generate a magnetic force that acts between the first and second magnets (28, 54). At least one of the first and second magnetic fields is variable.

A wind turbine rotor blade is provided including an inboard region and an outboard region including a spanwise section associated with the development of an unstable aeroelastic mode. The disclosed rotor blade includes a leading-edge corrective mass arranged within the spanwise section, which leading-edge corrective mass is adapted to move the center of mass of the spanwise section towards the leading edge in order to suppress the development of an unstable aeroelastic mode. A method of manufacturing a wind turbine rotor blade is also provided.

According to an embodiment, the method is for operating a wind turbine having a rotor with at least one rotor blade and a setting system which is configured to change the operation of the wind turbine. The method includes a step in which first trigger information is provided, wherein the first trigger information is representative of whether the torsional movement of at least one rotor blade exceeds a threshold. If this is the case, a first output signal is generated which is configured to cause the setting system to change the operation of the wind turbine in order to reduce the torsional movement of the at least one rotor blade.