A wind turbine system comprising a plurality of wind turbines mounted to a support structure including a tower, wherein each of the plurality of wind turbines includes a rotor and a power generation system driven by the rotor, and at least one of a rotor blade pitch adjustment means and a generator power control means. The system further includes control means that receives vibration data associated with the support structure and which is configured to determine a damping control command for a respective one of the plurality of wind turbines, wherein the or each of the wind turbines includes a damping controller that receives a damping control command and which is operable to apply a damping control input to one or both of the blade pitch adjustment means and the generator power control means so as to counteract the measured vibration of the support structure. A benefit of the invention is that the operation of the multiple turbines of the system is used to reduce the effects of structural vibration by damping that vibration in an active manner.

The present disclosure is directed to a system and method for assessing farm-level performance of a wind farm. The method includes operating the wind farm in a first operational mode and identifying one or more pairs of wind turbines having wake interaction. The method also includes generating a pairwise dataset for the wind turbines pairs. Further, the method includes generating a first wake model based on the pairwise dataset and predicting a first farm-level performance parameter based on the first wake model. The method also includes operating the wind farm in a second operational mode and collecting operational data during the second operational mode. Moreover, the method includes predicting a first farm-level performance parameter for the second operational mode using the first wake model and the operational data from the second operational mode. The method further includes determining a second farm-level performance parameter during the second operational mode. Thus, the method includes determining a difference in the farm-level performance of the wind farm as a function of the first and second farm-level performance parameters.

The lengths and/or chords and/or pitches of wind turbine or propeller blades are individually established, so that a first blade can have a length/chord/pitch that is different at a given time to the length/chord/pitch of a second blade to optimize performance and/or to equalize stresses on the system.

A virtual aerodynamic component for a wind turbine including at least one rotor blade connected to a hub. The at least one rotor blade defines an inner portion and a profiled outer portion. The virtual aerodynamic component includes one or more air-blowing units configured to provide a flow of air substantially opposed to an incoming wind. The flow of air defines the virtual aerodynamic component in front of the inner portion of the at least one rotor blade and provides for redirection of the incoming wind toward the profiled outer portion of the at least one rotor blade in an operational state and allows the incoming wind to flow toward the inner portion of the at least one rotor blade in a non-operational state. Further described is a wind turbine including the above-described virtual aerodynamic component and method for aerodynamic performance enhancement of an existing wind turbine.

A wind farm/park having a plurality of spatially distributed wind turbines, including at least one upstream wind turbine and at least one downstream wind turbine. Each wind turbine includes a rotor with at least two blades. At least one downstream wind turbine is affected under certain wind conditions by a wake region generated by the upstream wind turbine and containing helical vortex structures formed at the tip of the blades of the upstream wind turbine. A geometry or configuration of one or more of the rotor blades of the upstream wind turbine is different from a geometry or configuration of the other blade(s) of the upstream wind turbine thereby creating a fixed asymmetry in the blade configuration so as to accelerate destruction of vortices in the wake of the rotor of the upstream wind turbine by exciting a natural instability of the blade tip vortices.

There is provided a method for controlling a hydraulic pitch force system (220) so as to reduce or eliminate a decrease in hydraulic oil pressure (241) if a hydraulic system parameter value is outside a hydraulic system parameter range, the method comprising: Obtaining (690) the hydraulic system parameter value, and operating the hydraulic pitch force system (220) according to a reduced mode (692) if the hydraulic system parameter value is outside the hydraulic system parameter range, wherein in the reduced mode one or more pitch based activities are reduced (694) or suspended. An advantage thereof may be that it enables keeping the wind turbine in production in certain instances rather than shutting down the wind turbine. In aspects, there is furthermore presented a computer program product, a pitch control system (250) and a wind turbine (100).

A method of diagnosing a wind turbine power generating apparatus includes: an operation step of operating a pitch actuator corresponding to one of a plurality of wind turbine blades of the wind turbine power generating apparatus, without operating a pitch actuator corresponding to each of the wind turbine blades other than the one of the plurality of wind turbine blades; and a measurement step of measuring a response value indicating a response to operation of the pitch actuator corresponding to the one of the plurality of wind turbine blades. The operation step and the measurement step are performed repeatedly for each of the plurality of wind turbine blades, and the response value is obtained as data for health check of a blade pitch mechanism of the wind turbine power generating apparatus.

A method for damping an oscillation of a tower of a wind turbine is disclosed, wherein a pitch angle of each of the one or more rotor blades is individually adjustable, the method comprising damping the oscillation of the tower by pitching each rotor blade individually according to tower damping pitch control signals, wherein each tower damping pitch control signal comprises a first periodic component, where a first frequency of the first periodic component corresponds to a frequency difference between a tower frequency of the oscillation of the tower and a rotor frequency of a rotation of the rotor, and where a second periodic component has been reduced or removed. A second frequency of the second periodic component corresponds to a frequency sum of the tower frequency and the rotor frequency.

The lengths and/or chords and/or pitches of wind turbine or propeller blades are individually established, so that a first blade can have a length/chord/pitch that is different at a given time to the length/chord/pitch of a second blade to optimize performance and/or to equalize stresses on the system.

The present invention relates to a system for dynamic pitch control primarily for wind turbine blades, which system calculates the pitch position of the wind turbine blades independently, which control system performs feedback regulation. The object of the pending patent application is to perform effective pitch regulation and hereby to reduce thrust on the tower and the rotor. This can be achieved if the system performs feed forward regulation of the pitch of the blades, based on the load of the previous blade in substantially the same position. Hereby it can be achieved that the actual load on the previous blade has passed the same position in relation to the wind blowing around the wind turbine. Hereby it can be achieved that measured parameters are used after a short delay to perform a very precise and highly efficient adjustment of the next wind turbine blade passing the same position. The feed forward regulation can be combined with already existing control parameters for pitch control of wind turbine blades.