Provided is a method for detecting a wind gust that affects a wind turbine, wherein the wind turbine includes two or more blades which are coupled to a connection means so that the blades are essentially arranged in a common plane. The method including: i) measuring an event that at least one blade is at least partially out of the plane to obtain a measurement signal, ii) providing the measurement signal as a measurement input signal to an evaluation algorithm, iii) elaborating a detection result from the measurement input signal using the evaluation algorithm, and iv) comparing the detection result with a predefined wind gust threshold value (h) to determine, if a wind gust is detected. Furthermore, a wind gust detection system, a wind turbine that includes the system, and a wind turbine operating method are provided.

Described is a system for monitoring deflection of turbine blades of a wind turbine comprising a tower. The system comprises a position detecting apparatus mounted to the wind turbine, the position detection apparatus comprising position detection components each detecting a presence or absence of a corresponding one of the segments of the turbine blades; and a deflection controller configured to receive the presence or absence detection and to use the presence or absence detection to determine a distance of each of the segments of the turbine blades relative to the tower, whereby the distance of each of the segments of the turbine blades relative to the tower is representative of the deflection of the turbine blades.

A method for operating a wind turbine, in particular at a location characterized by a cold climate is provided. The method includes specifying an air density at a location of the wind turbine, setting a blade angle of an adjustable rotor blade based on an output power, torque and/or rotor speed. The method includes setting the blade angle as a function of a pitch characteristic curve which specifies the blade angle as a function of the output power, the torque and/or the rotor speed and as a function of the air density. According to the pitch characteristic curve, the blade angle has a minimum as a function of the air density in a region of a reference density of an atmosphere at the location which is characterized by a cold climate.

A method for controlling pitching of at least one rotor blade of a wind turbine includes receiving, via one or more position localization sensors, position data relating to the at least one rotor blade of the wind turbine. Further, the method includes determining, via a controller, a blade deflection signal of the at least one rotor blade based on the position data. Moreover, the method includes determining, via a computer-implemented model stored in the controller, a pitch command for the at least one rotor blade as a function of the blade deflection signal and an azimuth angle of the at least one rotor blade.

A method for the determination of the deflection of a wind turbine blade is provided. A distance between at least one root location towards a root end of the wind turbine blade and at least one tip location towards a tip end of the wind turbine blade is measured. A blade deflection profile is then calculated based on the measured distance between the root and tip locations and a known modal profile of the wind turbine blade.

A tower clearance real-time monitoring system (100) and a method therefor. The tower clearance monitoring system (100) comprises an image capture device (101), a blade position processing device (102) and a core algorithm processing device (103). The image capture device (101) is used to capture an image of a wind turbine in an operating state, and the image comprises a blade portion and a tower portion; The blade position processing device (102) is used to determine whether the captured image represents valid data so as to send valid data to the core algorithm processing device (103). The core algorithm processing device (103) is used to use valid data to calculate a tower clearance value for a blade, and to send a calculation result to a wind turbine main control system (104) of a wind turbine.

A method and device for determining a tower clearance of a wind turbine. The method comprises: acquiring an image of a wind turbine in operation (S10), the image comprising the tips of blades (2) and a tower (1) of the wind turbine; determining the positions of the tips of the blades (2) of the wind turbine in the image acquired (S20); identifying the edges of the tower (1) in the image acquired (30); and calculating, on the basis of the positions of the tips of the blades (2) and the edges of the tower (1) that have been determined, the distance from the tips (2) of the blades (2) to the edges of the tower (1) to acquire a tower clearance (S40). The employment of the method and device for determining the tower clearance for the wind turbine allows the real-time determination of the tower clearance for the wind turbine, thus effectively preventing the blades (2) from hitting the tower.

Described is a system for monitoring deflection of turbine blades of a wind turbine comprising a tower. The system comprises a position detecting apparatus mounted to the wind turbine, the position detection apparatus comprising position detection components each detecting a presence or absence of a corresponding one of the segments of the turbine blades; and a deflection controller configured to receive the presence or absence detection and to use the presence or absence detection to determine a distance of each of the segments of the turbine blades relative to the tower, whereby the distance of each of the segments of the turbine blades relative to the tower is representative of the deflection of the turbine blades.

In a wind turbine comprising a tower supporting a nacelle, at least one blade rotationally attached to the nacelle and having a blade-tip section, a system for measuring the separation distance between the tower and the blade-tip-section of the wind turbine, comprising an indicator stripe on the surface of the blade-tip section, an indicator ring encircling the tower, a camera in the nacelle and positioned such that the blade-tip section and the indicator ring are within the camera's field of view when the blade-tip is at its closest approach position to the tower, the camera digitally recording an image of its field of view at this closest approach position, the distance between indicator ring and camera being essentially equal to the distance between the indicator stripe and the camera at this closest approach position, and an image processor and tip-tower clearance calculator unit receiving the digitally recorded image and calculating a physical separation distance between the indicator stripe and the indicator ring using the digitally recorded image information, the physical separation distance being indicative of the blade tip-tower clearance.

Described is a system for monitoring deflection of turbine blades of a wind turbine comprising a tower. The system comprises a position detecting apparatus mounted to the wind turbine comprising a plurality of position detection components each collecting data regarding a field of detection through which a segment of the turbine blades passes, wherein the position detection components are monitoring distinct fields of detection to collect distances of a plurality of segments of each one of the turbine blades travelling through the fields of detection. The system further comprises a deflection controller configured to receive the collected distances and to determine deflection of the turbine blades accordingly. An associated method comprises collecting distances of a plurality of distinct segments of the turbine blades when the turbine blades travel within a plurality of fields of detections, and processing the collected distances to determine clearance between the turbine blades and the tower.