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.

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.

A system and method for monitoring and controlling the deflection of rotor blades of a wind turbine so as to prevent tower strikes is disclosed. The method includes operating the wind turbine at standard pitch angle settings. Another step includes monitoring a loading condition of the wind turbine over a predetermined time period. A further step includes tracking a number of wind condition deviations of a certain magnitude occurring during a predetermined time period. The method also include altering one or more of the standard pitch settings of the rotor blades in response to the number of wind condition deviations exceeding a wind deviation threshold and/or the loading condition exceeding a loading threshold as an exceedance indicates an increased probability of rotor blade deflection. The method further includes performing one or more additional corrective actions so as to reduce the probability of a rotor blade tower strike.

A structure adapted to traverse a fluid environment exerting an ambient fluid pressure is provided. The structure includes an elongate body extending from a root to a wingtip and encapsulating at least one interior volume containing an interior fluid exerting an interior fluid pressure that is different from the ambient fluid pressure. A method of retrofitting a structure adapted to traverse a fluid environment exerting an ambient fluid pressure, the structure comprising an elongate body extending from a root to a wingtip and having at least one interior volume is also provided. The method includes sealing the elongate body to encapsulate the at least one interior volume containing an interior fluid; associating at least one valve with the at least one interior volume; and modifying interior fluid content via the at least one valve to produce an interior fluid pressure that is different from the ambient fluid pressure.

A structure for a turbine, the structure comprising a body having a multi-layer construction including an interior layer with substantially uniform concentrations throughout of facultative anaerobic organisms (FAO) that have gene sets capable of producing the enzyme urease and/or the proteins purloin, lustre A and perlustrin, along with glucose, and non-uniform concentrations throughout of a structural composition, the structural composition including a chitin-based component with silk fibronectin and water; an exterior layer of urea, water, calcium ions and facultative anaerobic organisms (FAOs) including urease, aragonite; and a binding layer of conchiolin protein intermediate the interior layer and the exterior layer. The facultative anaeorobic organisms (FAOs) are organisms classified in one of the Saccharomyces, Escherichia and Bacillus genuses.

Method of operating a wind turbine having a tower, a rotor with a plurality of blades arranged on the tower, one or more pitch systems for pitching the blades, a system for determining an instantaneous representative wind speed, and a system for determining a distance between a blade and the tower. The method comprises determining the instantaneous representative wind speed, and determining the distance between the tower and one of the blades when said blade is in the shadow of the tower. The method further comprises determining a tower distance pitch adjustment depending on the determined distance between the tower and the blade in the shadow of the tower and on the determined instantaneous representative wind speed. The method still further comprises the one or more pitch systems applying the determined tower distance pitch adjustment to at least the next blade to be in the shadow of the tower.

An amount of the deflection of the blades of a rotor of a wind turbine of the type including a tower and a nacelle mounted to the top of the tower, the rotor being rotatably connected to the nacelle for rotating about a rotor axis and having a plurality of equally spaced blades includes positioning video cameras on the rotor 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 and carrying out an analysis of the images of the tip to determine a position of the tip and hence the deflection of the tip time synchronized analyzed optionally with external data providing load, capacity, power produced or environmental data.

A wind turbine that includes a plurality of turbine blades. Each of the plurality of turbine blades includes a plurality of openings that extend through each of the plurality of turbine blades, the plurality of openings are adapted to be opened or closed, and at least one of the plurality of openings is adapted to be opened to allow air to flow therethrough.

A wind turbine (1) is provided, having a wind turbine tower (2) and at least one rotatable blade (5), and further comprising a system for measuring rotor blade vibration of said wind turbine. The system comprises at least one Doppler radar unit (7) operatively configured to emit and receive radar signals, the radar unit being mounted on the wind turbine tower at a position above the lowest position of the at least one blade, the radar unit being positioned so as to measure reflections of an emitted radar signal from the turbine blade. A processing unit is configured to receive measurement data from the radar unit and to determine, by analysis of Doppler shift in received radar signals relative to transmitted signals due to movement of the blade towards or away from the turbine tower, the velocity of the blade in the direction towards or away from the turbine tower. Using a radar unit to measure blade velocity allows a determination to be made of the vibrations occurring in the blade without needing an internal sensor in the blade. This reduces manufacturing and maintenance costs of the blades since sensors in the blades will not need to be replaced, and sensors positioned on the tower are easier to replace in the field.