The present invention relates to a damper unit for damping oscillations of a tower structure when secured thereto, the damper unit comprising a damper unit structure adapted for attachment to the tower structure, a pendulum structure, a suspension arrangement for suspending the pendulum structure from the damper unit structure such that the pendulum structure is allowed to displace from a neutral position for the pendulum structure, the suspension arrangement comprising one or more wires for suspending the pendulum structure, a sensor adapted for measuring oscillations of the tower structure, and tuning means configured for adjusting the natural frequency of the suspended pendulum structure in response to measured oscillations of the tower structure. The present invention further relates to an associated method.

A device and a method of controlling blade instabilities of a wind turbine is provided. The method including the following steps: defining at least one preliminary overspeed threshold value; defining a fluttering rotor speed at and above which a predetermined fluttering of at least one of the blades occurs, the fluttering rotor speed is defined as a function of the pitch angle and/or as a function of the wind speed; setting a final overspeed threshold value to be equal to or smaller than a minimum rotor speed of the at least one preliminary overspeed threshold value and the fluttering rotor speed at the actual pitch angle and/or at the actual wind speed; and controlling the rotor speed to not exceed the final overspeed threshold value.

A rotation speed avoidance 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 whether the required power value upper limit is in a power avoidance interval corresponding to a rotation speed avoidance interval; and when the required power value upper limit is in the power avoidance interval, setting the maximum allowable power value of a wind turbine generator system to be a lower boundary value of the power avoidance interval. An upper boundary value of the power avoidance interval is a power value determined on the basis of an upper boundary value of the rotation speed avoidance interval, and the lower boundary value of the power avoidance interval is a power value determined on the basis of a lower boundary value of the rotation speed avoidance interval, wherein the rotation speed avoidance interval and the power avoidance interval are open intervals. By means of the control method, an operation range of the rotation speed of a wind turbine generator system in a power-limited operation state can be prevented from overlapping with a rotation speed avoidance interval, thereby preventing resonance of the generator system, load increase or other safety problems. In addition, the present invention further relates to an apparatus for implementing the control method, and a wind turbine generator system.

A system and method are provided for controlling a wind turbine. Accordingly, a controller of the wind turbine detects a transient grid event and generates a torque command via a drive-train-damper control module. The torque command is configured to establish a default damping level of a torsional vibration resulting from the transient grid event. The controller also determines at least one oscillation parameter relating to the torsional vibration and determines a target generator torque level based thereon. The target generator torque level corresponds to an increased level of damping the torsional vibration relative to the default damping level.

A wind turbine generator system and a rotation speed avoidance control method therefor. The method comprises: according to statistical information of the rotation speed of a generator being in a rotation speed avoidance interval, identifying whether a wind turbine generator system repeatedly falls within the rotation speed avoidance interval; and when it is determined that the wind turbine generator system repeatedly falls within the rotation speed avoidance interval, adjusting a rotation speed avoidance control parameter of the wind turbine generator system according to the statistical information of the rotation speed being in the rotation speed avoidance interval. Correspondingly, further provided is a rotation speed avoidance control apparatus for a wind turbine generator system.

The system and method described herein provide grid-forming control of a power generating asset having a generator, such as a double-fed generator, connected to a power grid. Accordingly, a stator-frequency error is determined for the generator. The components of the stator frequency error are identified as a damping component corresponding to a tower damping frequency and a stator component. Based on the stator component, a power output requirement for the generator is determined. This power output requirement is combined with the damping power command to develop a consolidated power requirement for the generator. Based on the consolidated power requirement, at least one control command for the generator is determined and an operating state of the generator is altered.

The disclosure relates to a method for operating a wind turbine wherein the method includes: operating the wind turbine over an operating period in accordance with a control strategy, providing one or more input values representing a load acting on at least one component of the wind turbine and providing uncertainties of the input values, determining, based on the input values, an aggregated load value representing an aggregated load acting on the at least one component of the wind turbine over an aggregation period, determining, based on the uncertainties of the input values, an uncertainty of the aggregated load value, determining a statistical load aggregate from the aggregated load value and the uncertainty of the aggregated load value, adjusting the control strategy based on the statistical load aggregate. The disclosure further relates to a wind turbine and a wind farm configured to perform the above method.

Provided is a method for controlling a wind turbine, in particular an electric generator of said wind turbine. The method includes an optimization during which a suitable operating parameter for controlling said wind turbine or generator thereof is determined, in particular in an iterative manner. The optimization includes providing a multidimensional space comprising a plurality of parameters; providing an objective function for said multidimensional space, e.g., a simplex has a shape of a triangle or a tetrahedron; and determining one parameter of said multidimensional space as a suitable operating parameter by applying said objective function to said multidimensional space, in particular in an iterative manner. The method includes selecting a suitable operating parameter as an operating parameter for said wind turbine or generator thereof; and operating said wind turbine or generator based on said operating parameter, in particular by controlling a converter connected to said generator.

There is provided a method of avoiding edgewise vibrations during a non-operational period of a wind turbine. The method comprises defining a non-operational period for a wind turbine arranged at a specific site, determining expected wind conditions at the specific site during the non-operational period and defining a plurality of potential yaw orientations for the wind turbine. The method further comprises determining the relative probability of edgewise vibrations occurring during the non-operational period for each potential yaw orientation based upon the expected wind conditions during the non-operational period, determining one or more preferred yaw orientations, which are the yaw orientations in which the probability of edgewise vibrations occurring is lowest, and arranging the wind turbine in one of the preferred yaw orientations during the non-operational period.

Method for controlling a rotor speed of a rotor of a wind turbine at rated or curtailed operation conditions the rotor being an aerodynamic rotor having one or a plurality of rotor blades, and the wind turbine further having a tower and a generator wherein a pitch control provides a pitch angle set value depending on an actual rotor speed for setting a pitch angle of the rotor blades, a main control provides a main power or torque set value for controlling the power or torque of the generator, and an additional control provides an additional power or torque set value depending on the actual rotor speed , wherein the additional power or torque set value is provided as an offset value and is added to the main power or torque set value respectively, wherein the additional power or torque set value is calculated depending on a control deviation of the rotor speed, and optionally, in combination with the additional control, or instead of it, a maximum power control provides a maximum power value as a varying value for limiting an output power of the generator and the maximum power value is calculated depending on a predetermined power limit value, and depending on a predetermined reference duration, in order to provide for the reference duration an average power reaching or at least not exceeding the predetermined power limit value.