The present invention relates to a method for controlling a wind turbine, in particular a method for controlling pitch of one or more blades of a wind turbine and related system. The method comprises collecting first data indicative of a dynamic condition of the first wind turbine blade and the rotor, the first data comprising rotor data and first deflection data, the rotor data being indicative of the azimuth position and rotational velocity of the rotor in a rotor plane perpendicular to the rotor axis, and the first deflection data being indicative of the position, speed and acceleration of one or more parts of the first wind turbine blade. Further, the method comprises calculating an expected tower clearance distance at a later time of tower passage for the first wind turbine blade based on the first data including acceleration of one or more parts of the first wind turbine blade, and performing measures to prevent tower collision, if the expected tower clearance distance fulfills a collision risk criterion.

A method of determining a distance between a rotor blade tip and a tower of a wind turbine includes: estimating the distance based on a strain measurement; measuring the distance; correcting an estimation procedure based on the estimated distance and the measured distance; and deriving a corrected distance based on the corrected estimation procedure.

An acoustic monitoring system and method for the health status of an offshore wind turbine and an ocean wave are provided. The acoustic monitoring system includes a first laser transmitter, a second laser transmitter, a telephoto camera provided at a hub, a vibration detection sensor provided on a tower of a wind turbine, and four acoustic detection sensors arranged at an interval of 90? along the circumference of the tower. The first and second laser transmitters are arranged at the bottom of a nacelle of the wind turbine and emit laser lights vertically downward. The first laser transmitter, the second laser transmitter, the telephoto camera, the vibration detection sensor, and the acoustic detection sensors are connected to a data acquisition and conversion module through a transmission module. The acoustic monitoring system combines laser light detection with acoustic signal feature detection to improve stability and safety of the offshore wind turbine.

A rotor blade for addressing the deflection of rotor blades of a wind turbine. The rotor blade includes a plurality of exterior surfaces defining a blade body having a pressure side, a suction side, a leading edge and a trailing edge. The blade body extending between a blade tip and a blade root. The blade body including a breakaway tip portion defined by a predetermined breaking point. The breakaway tip portion is configured to break away from the remaining portion of the blade body when subject to a predetermined tower strike load. A wind turbine including the rotor blade configuration is further disclosed.

In a wind turbine of the type including a tower and a nacelle with the rotor being rotatably connected to the nacelle for rotating about a rotor axis and having a plurality of equally spaced blades, there is provided a method of detecting damage to a rotor requiring replacement. The method includes positioning video cameras on each of the blades at a root of a respective one of the blades so as to provide a line of sight of the camera along the respective one of the blades to the tip to obtain a video image of the rotor and tip as they rotate. From the videos an analysis is carried out of the images of the tip at a common location spaced away from the tower to determine a position of the tip and hence the deflection of the tip which is indicative of damage.

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.

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.

The invention allows orientation of the platform (1) in order to obtain conditions of maximum efficiency in the wind turbine (16). It comprises first sensors (8) for detecting an effective rotation axis angle (?) formed between the rotation axis (2) and a horizontal plane (24); second sensors (9) for detecting wind direction (23); platform orientation means (11) for modifying the effective rotation axis angle (?); and at least one control unit (12) adapted for receiving a first input (13) from the first sensors (8) and a second input (14) from the second sensors (9) and, based on said inputs (13, 14), transmitting orders to the platform orientation means (11) and yaw mechanism.

A method of determining a blade clearance during operation of a wind turbine is provided, the blade clearance corresponding to a distance between a rotor blade and a tower of the wind turbine. The method includes (a) detecting a rotor blade velocity, (b) emitting a first signal from an observer location, the first signal having a first frequency, (c) receiving a second signal at the observer location, the second signal being reflected from the rotor blade when the first signal impinges on the rotor blade, (d) determining a Doppler shift of the second signal relative to the first signal, and (e) determining the blade clearance based on the first frequency, the Doppler shift, the observer location, and the rotor blade velocity, wherein the step of determining the blade clearance utilizes a mathematical model. A corre-sponding system and a wind turbine comprising such a system are also provided.

The present invention relates to a method for controlling a wind turbine, in particular a method for controlling pitch of one or more blades of a wind turbine and related system. The method comprises collecting first data indicative of a dynamic condition of the first wind turbine blade and the rotor, the first data comprising rotor data and first deflection data, the rotor data being indicative of the azimuth position and rotational velocity of the rotor in a rotor plane perpendicular to the rotor axis, and the first deflection data being indicative of the position, speed and acceleration of one or more parts of the first wind turbine blade. Further, the method comprises calculating an expected tower clearance distance at a later time of tower passage for the first wind turbine blade based on the first data including acceleration of one or more parts of the first wind turbine blade, and performing measures to prevent tower collision, if the expected tower clearance distance fulfills a collision risk criterion.