A method of controlling an offshore wind turbine subjected to a sea wave for damping at least one mechanical vibration is provided, the method including yawing the nacelle to a favorable orientation (a) derived based on information regarding a sea wave, in order to improve damping of the vibration.

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 noise reduction element extends between a first end and a second end in a first direction. The noise reduction element extends between a third end and a fourth end in a second direction perpendicular to the first direction. The noise reduction element includes a base part configured to be attached to a trailing edge of a wind turbine blade. The base part has a first base part surface and a second base part surface. The base part extends between the first end and a first position in the first direction. The noise reduction element includes a first serration part having a serration pressure surface and a serration suction surface and extending in the first direction between the first position and the second end. The first serration part has a thickness in a third direction between the serration pressure surface and the serration suction surface.

A rotation speed exclusion control method for a wind turbine generator system. The method comprises: when a power-limited operation instruction is received, determining a power value upper limit required by the instruction; determining that the required power value upper limit is in a power exclusion interval corresponding to a rotation speed exclusion interval; and when the required power value upper limit is in the power exclusion interval, setting the maximum allowable power value of a wind turbine generator system to be a lower boundary value of the power exclusion interval.

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 of controlling airborne tonal noise which originates from a component of a wind turbine, the wind turbine comprising a vibration control system comprising a plurality of actuators. The method comprising identifying a first operating state of the wind turbine; and selecting a first set of one or more of the actuators on the basis of the identified first operating state. Each actuator of the first set is operated to apply a vibration control oscillation to the component in phase opposition to a vibration of the component, thereby damping the vibration of the component and in turn reducing airborne tonal noise originating from the component. A change of the wind turbine to a second operating state is detected, then a second set of one or more of the actuators is selected on the basis of the identified second operating state. Each actuator of the second set is operated to apply a vibration control oscillation to the component in phase opposition to a vibration of the component, thereby damping the vibration of the component and in turn reducing airborne tonal noise originating from the component.

A wind turbine flutter suppression method includes: determining a nacelle-wind direction angle between a wind direction and a nacelle direction; and determining a pitching method for changing pitch angles according to the nacelle-wind direction angle. The pitching method includes a speed-controlled pitching scheme and a pitch-angle-sequence-controlled pitching scheme. The speed-controlled pitching scheme includes regulating pitch angles of blades of the wind turbine according to a rotor speed of the wind turbine to keep the rotor speed within a preset speed range until flutter of the wind turbine is suppressed. The pitch-angle-sequence-controlled pitching scheme includes performing a pitching operation on the pitch angles of the blades of the wind turbine according to preset pitching rules until the flutter of the wind turbine is suppressed.

A method is for operating a wind turbine having a tower, a rotor with a rotor blade and a generator coupled to the rotor. The wind turbine further includes a pitch setting system for changing the pitch angle of the rotor blade and a generator controller for controlling the generator torque. The method includes providing first information representative of at least two motion variables. The motion variables are motion variables of an oscillation of the tower and/or of an oscillation of the rotor blade. Then, an operating setpoint is determined for the pitch setting system and the generator controller depending on the first information. The operating setpoint is determined such that, when the pitch setting system and/or the generator controller is operated according to the respective operating setpoint, it sets the pitch angle of the rotor blade or the generator torque, respectively, in order to damp the oscillation.

The present disclosure relates to the technical field of wind turbines, and in particular to a standby power supply control device, including: a nacelle vibration detection unit, configured to monitor vibrations of a nacelle of a wind turbine and send a first vibration signal obtained by monitoring a standby power supply start/shutdown control unit; and the standby power supply start/shutdown control unit, configured to acquire the first vibration signal, determine a vibration state of blades on the wind turbine according to the first vibration signal and send a start command to a standby power supply when the vibration state is abnormal. The standby power supply start/shutdown control unit is further configured to acquire comprehensive vibration information, determine a vibration suppression result of the wind turbine according to the comprehensive vibration information and send a shutdown command to the standby power supply when the vibration suppression result is vibration suppression completed.

An assembly and associated method of operation for a wind turbine blade of a wind turbine includes a vibration mitigating device configured to be arranged around the blade. The vibration mitigating device includes a main body configured to extend chord-wise around and encircle the blade, the main body having at least one inflatable body. Inflatable air flow modifying elements extend radially outward from the main body. A pressure source is connectable to the inflatable body and the air flow modifying elements to inflate the inflatable body and the airflow modifying elements based on measurements of a sensor system that monitors a condition of the wind turbine or an environmental condition around the wind turbine.