The present disclosure relates to a method for determining reliability of one or more load sensors in a wind turbine. The method comprises measuring loads with the load sensors during operation of the wind turbine; determining in-plane moments based on the measured loads; selecting the in-plane moments with 1 p frequency; and comparing the selected in-plane moments with theoretical in-plane moments due to a mass of the blade. The method then comprises determining that the load sensors have reduced reliability if the selected in-plane moments deviate from the theoretical in-plane moments by more than a first threshold value. The present disclosure also relates to wind turbine systems incorporating load sensors and methods for on-line determination of correct functioning of load sensors mounted on a wind turbine blade.

A method of controlling at least one adaptable airflow regulating system, in particular spoiler and/or flap, of at least one rotor blade of a wind turbine having a wind turbine tower includes: determining a quantity related to a distance between the rotor blade and the wind turbine tower; controlling the airflow regulating system based on the quantity.

A method for damping vibration in a wind turbine including aerodynamic devices for influencing the airflow flowing from the leading edge of a rotor blade of the wind turbine to the trailing edge of the rotor blade, each aerodynamic device being movable by an actuator between a first protruded configuration and a second retracted configuration is provided. The method includes measuring vibrations in the wind turbine, if the measured vibrations are greater than a threshold within a predefined frequency band, moving a portion of the aerodynamic devices to the second retracted configuration and continuing to measure vibrations, if the measured vibrations are still greater than a threshold within a frequency band, reducing the pitch angle interval of the blade and continuing to measure vibrations, if the measured vibrations are still greater than a threshold within a frequency band, moving all the aerodynamic devices to the second retracted configuration.

Provided is a main bearing for a wind turbine, including a stationary ring and a rotating ring to be coupled to a rotor, whereby the main bearing is a fluid film bearing including several bearing units arranged at the stationary ring around the circumference on both sides of the rotating ring, for radially and axially bearing the rotating ring, and further including a load measurement arrangement for determining measurement data which are a measure for the load applied to or resting on at least one of the axial or radial bearing units.

A method for detecting a sensor malfunction of a load sensor of a wind power installation having a rotor and at least one rotor blade, wherein the load sensor is configured to detect a loading variable of one of the rotor blades, and the sensor malfunction involves the functional freezing of a sensor signal from the load sensor, such that it remains temporally constant, wherein at least one loading variable of the rotor blade is estimated and, in the event that the sensor signal is temporally constant, a comparability test is executed wherein, according to the at least one estimated loading variable, a check is executed as to whether a non-constant sensor signal is to be anticipated, and a sensor malfunction is identified by reference to the comparability test.

A method for detecting a failure condition in one or more components of a wind turbine is provided. The method includes actuating, via a controller, an impact device to generate a vibration having a vibration frequency and a vibration magnitude in the one or more components. The method further includes receiving data indicative of the vibration frequency and the vibration magnitude from a sensor communicatively coupled to the controller. The method further includes determining, via the controller, whether the data indicative of the vibration frequency and/or the vibration magnitude is outside of a predetermined vibration range for the one or more components.

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.

The present invention discloses methods and systems for detecting the health status of a bolt which fastens a rotor blade of a wind turbine. Values of the axial stress/strain of the bolt and motion and orientation data are acquired in different aerial orientations. Values of the prestress/strain and load-stress/strain are obtained using the values of the axial stress/strain and the motion and orientation data. Values of the prestress/strain and load-stress/strain are compared with the reference values. The health status of the bolt, rotor blade, and the wind turbine system is determined based on the comparison results. The method is noninvasive and doesn't affect the function and performance of the bolt and the turbine system.

One object is to promptly and accurately sense an abnormal state of a wind turbine driving device. The wind turbine driving device includes a driving device body and a sensor. The driving device body is installed in one structure at a movable section of a wind turbine. The driving device body includes a meshing portion meshing with a ring gear installed in the other structure at the movable section of the wind turbine. The sensor measures a change in installation state of the driving device body with respect to the one structure.

Provided is a main bearing for a wind turbine, including a stationary ring and a rotating ring to be coupled to a rotor, whereby the main bearing is a fluid film bearing including several bearing units arranged at the stationary ring around the circumference on both sides of the rotating ring, for radially and axially bearing the rotating ring, and further including a load measurement arrangement for determining measurement data which are a measure for the load applied to or resting on at least one of the axial or radial bearing units.