Systems, methods, and kits for reducing structural vibrations on wind turbine blades are provided. The actual dynamic structural conditions of a wind turbine blade can be used as a feedback mechanism. A flow control device and a sensor can be installed on a wind turbine blade, and a closed loop control system in operable communication with the flow control device and the sensor can be used to provide closed loop control.

A sensor system for a wind turbine, comprising: a blade load sensor; a blade temperature sensor configured to provide a temperature measurement of an associated blade; a load calculation module configured to output a temperature-corrected blade load value; and a processing unit interfaced with the temperature sensor. The processing unit includes a temperature estimator configured to determine an estimated temperature of the wind turbine blade based on at least one wind turbine parameter; and a comparator configured to generate a fault signal based on a comparison between the blade temperature measurement and the estimated blade temperature. The invention also resides in a corresponding method.

The present invention provides a method of operating a wind turbine. The wind turbine comprises at least one rotatable blade. The method comprises the steps of providing a load sensor configured to generate a load signal representing loading on the blade, generating a first load signal when the blade is in a first position, and generating a second load signal when the blade is in a second position. Additionally, the method comprises steps of detecting a rotational speed of the blade, calculating a weight force on the blade based on the first and the second load signal, and calculating a centrifugal force on the blade based on the first and the second load signal. Subsequently, the weight force is compared with a predetermined weight force, and the centrifugal force is compared with a predetermined centrifugal force at the detected rotational speed. Finally, a risk of ice throw is determined based on the comparisons of the weight force and the centrifugal force with the predetermined forces.

The invention relates to an assembly for monitoring and/or controlling a wind turbine. The assembly for monitoring and/or controlling a wind turbine comprises: an arrangement of two strain sensors, in particular three strain sensors, which detects blade bending moments of a rotor blade of a wind turbine in at least two different spatial directions; a first fibre optic vibration sensor for detecting vibrations of the rotor blade in a first spatial direction; and at least one second fibre optic vibration sensor for detecting vibrations of the rotor in a second spatial direction, which differs from the first spatial direction.

A method for controlling loads of a wind turbine includes receiving sensor signals from one or more sensors being indicative of a movement of a nacelle of the wind turbine from a reference point. More particularly, the movement corresponds, at least, to a tilt and/or a displacement of the wind turbine tower and/or nacelle. The method also includes generating a deflection profile of the tower along its overall length from a bottom end to a top end thereof based on the sensor signals. Further, the method includes determining at least one of a thrust or a tower load of the wind turbine from the deflection profile. In addition, the method includes implementing a control action for the wind turbine based on the thrust and/or the tower load.

A sensor system for a wind turbine blade, the system comprising: a blade load sensor providing a load measurement; a processing unit interfaced with the blade load sensor and configured to provide a corrected load parameter as an output. The processing unit includes: an axial force estimation module that determines an estimated axial force on the wind turbine blade in a direction along the length of the blade; and a load calculation module that 10 determines the corrected load parameter based on the estimated axial force and the load measurement of the blade load sensor.

A method of measuring load on a wind turbine, and a wind turbine for such load measuring, are disclosed. The wind turbine comprises at least one rotor blade and at least one load sensor associated with the rotor blade. At least one load sensor is located at a position on the rotor blade remote from both a flap bending moment axis and an edge bending moment axis of the rotor blade. At the position, a flap bending moment component and an edge bending moment component of the load on the rotor blade are measurable. A load value is measured from the load sensor, and the measured load value is used to determine a flap bending moment component of the load and an edge bending moment component of the load, and optionally or additionally an axial force component of the load.

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 controlling loads of a wind turbine includes receiving sensor signals from one or more sensors being indicative of a movement of a nacelle of the wind turbine from a reference point. More particularly, the movement corresponds, at least, to a tilt and/or a displacement of the wind turbine tower and/or nacelle. The method also includes generating a deflection profile of the tower along its overall length from a bottom end to a top end thereof based on the sensor signals. Further, the method includes determining at least one of a thrust or a tower load of the wind turbine from the deflection profile. In addition, the method includes implementing a control action for the wind turbine based on the thrust and/or the tower load.

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.