The invention provides a method for stabilising a wind turbine blade (106), the method comprising, attaching (S2) an air blowing arrangement (201) to the blade, detecting (S4) an oscillation of the blade, and operating (S5) the attached air blowing arrangement to provide a thrust to counteract the oscillation.

A method of evaluating quality of a wind turbine blade which has a hollow structure where an interior space of the wind turbine blade is surrounded by an outer skin which includes a laminated body includes: setting a scanning line on at least a part of an inner wall surface or an outer wall surface of the outer skin; and moving an ultrasound probe along the scanning line; generating a cross-sectional image corresponding to the scanning line, on the basis of a position of the ultrasound probe or a reflection echo to detect an indication whose echo level is greater than a first threshold; obtaining an inclination of the indication with respect to a reference line as a first parameter; and evaluating the lifetime or the breakage risk of the wind turbine blade on the basis of the first parameter.

A one-dimensional (1D) and two-dimensional (2D) scan scheme for a tracking continuously scanning laser Doppler vibrometer (CSLDV) system to scan the whole surface of a rotating structure excited by a random force. A tracking CSLDV system tracks a rotating structure and sweep its laser spot on its surface. The measured response of the structure using the scan scheme of the tracking CSLDV system is considered as the response of the whole surface of the structure subject to random excitation. The measured response can be processed by operational modal analysis (OMA) methods (e.g., an improved lifting method, an improved demodulation method, an improved 2D demodulation method). Damped natural frequencies of the rotating structure are estimated from the fast Fourier transform of the measured response. Undamped full-field mode shapes are estimated by multiplying the measured response using sinusoids whose frequencies are estimated damped natural frequencies.

A method and apparatus for inspecting a wind turbine blade. The method includes: acquiring a sound signal generated by an impingement of wind on the wind turbine blade using a sound acquisition device; generating a frequency spectrogram corresponding to the sound signal; and obtaining a damage recognition result of the wind turbine blade from the frequency spectrogram by performing image recognition on the frequency spectrogram based on a damage recognition model. With the method, a damage type of the wind turbine blade is accurately recognized based on the frequency spectrogram without manual inspection. Therefore, human resources are saved. In addition, the health state of the wind turbine blade can be monitored in real time.

A wind turbine blade measurement system for optically determining a torsion of a wind turbine blade is disclosed. The wind turbine blade measurement system comprises: a wind turbine blade, which is configured to be mounted to a hub of a wind turbine, a first camera, and an auxiliary camera. The first camera is mounted in a fixed position on a support structure on an exterior surface of the root section of the wind turbine blade and arranged so as to measure along the spanwise direction of the wind turbine blade. The auxiliary camera is arranged at a position outside of the wind turbine blade, the auxiliary camera being arranged so as to being able to carry out measurements of a plurality of sets of markers arranged on the surface of the wind turbine blade and an orientation of at least one of the support structure and the first camera.

A method for identifying underperforming agents in a multi-agent cooperative system includes receiving information relating to the performance of each agent in the multi-agent system, calculating an estimated extracted resource value of each agent based on the received information, comparing the estimated extracted resource value of each agent to a threshold value, calculating a performance index based on the comparison and identifying an agent as an under-performing agent based on the performance index. A system for identifying under-performing agents in a plurality of agents in a multi-agent cooperative system includes a performance analyzing processor, a communications port for receiving state information for each agent and control information for each agent, a classifier for identifying a subset of agents in the plurality of agents that are performance comparable and an optimizer configured to identify an under-performing agent of performance comparable agents and generate updated control information for the identified under-performing agent.

A system and method are provided for controlling a wind turbine of a wind farm. Accordingly, a controller implements a first model to determine a modeled performance parameter for the first wind turbine. The modeled performance parameter is based, at least in part, on an operation of a designated grouping of wind turbines of the plurality of wind turbines, which is exclusive of the first wind turbine. The controller then determines a performance parameter differential for the first wind turbine at multiple sampling intervals. The performance parameter differential is indicative of a difference between the modeled performance parameter and a monitored performance parameter for the first wind turbine. A second model is implemented to determine a predicted performance parameter of the first wind turbine at each of a plurality of setpoint combinations based, at least in part, on the performance parameter differential the first wind turbine. A setpoint combination is then selected based on the predicted performance parameter and an operating state of the first wind turbine is changed based on the setpoint combination.

Testing data transfer at the application layer of a wind power surveillance computer system. One technique includes preparing a test message with a message id, transferring the test message from a first computer entity to a second computer entity, stamping the test message with a time stamp, when transfer is initiated, stamping the test message with a transfer id and a corresponding transfer time stamp, when the test message is received at the second entity, transferring the test message from the second computer entity at the application layer to the first computer entity, stamping the test message with an arrival time stamp, when the test message arrives at the first entity, storing the message id and the transfer id with corresponding time stamp and corresponding transfer time stamp, and the arrival time stamp, and comparing the stored time stamp with the transfer time stamp and with the arrival time stamp.

Methods for assessing the useful life that may remain for a portion of a wind turbine support structure. The methods may include identifying an overall expected useful life for the portion of the support structure and estimating an expended life from the extent of loading that has occurred to the portion of the support structure during the operative life of a wind turbine. The useful life remaining for the portion may be determined by subtracting the expended life from the overall expected useful life.

A monitoring system (100) monitors displacement of a wind turbine tower and includes at least one plumb bob with an upper part and a lower part, each plumb bob being configured to be pivotally suspended at its upper part, via a suspension device, from a point above so as to attain a rest position in a rest situation, and each said plumb bob has one or more sensing surfaces (12, 12′). One or more suspension devices means (10) suspend the at least one plumb bob. Two or more sensors (14, 14′, 14″), each being configured to sense, in a specific sensing direction (16, 16′, 16″), a distance to a plumb bob, provide displacement data. At least two of the two or more sensors (14, 14′, 14″) are arranged in a sensing vicinity of a plumb bob, with at least two of the specific sensing directions (16, 16′, 16″) not being parallel to each other. The monitoring system includes a control unit (18) configured to receive the displacement data from two or more of the sensors, and a device for reporting, to an external unit (20), parameter(s) representing displacement of a wind turbine tower.