Provided is a method of monitoring the structural integrity of a supporting structure of a wind turbine, which method includes the steps of determining a fore-aft tower oscillation frequency; determining a side-to-side tower oscillation frequency; computing a working structural indicator value from the fore-aft tower oscillation frequency and the side-to-side tower oscillation frequency; comparing the working structural indicator value to a reference working structural indicator value; and issuing an alarm if the difference between the working structural indicator value and the reference structural indicator value exceeds a predefined threshold. Also provided is a system for monitoring the structural integrity of a supporting structure of a wind turbine, a wind turbine, and a computer program product for carrying out the steps of the inventive method.

Provided is a method of monitoring the structural integrity of a supporting structure of a wind turbine, which method includes the steps of determining a fore-aft tower oscillation frequency; determining a side-to-side tower oscillation frequency; computing a working structural indicator value from the fore-aft tower oscillation frequency and the side-to-side tower oscillation frequency; comparing the working structural indicator value to a reference working structural indicator value; and issuing an alarm if the difference between the working structural indicator value and the reference structural indicator value exceeds a predefined threshold. Also provided is a system for monitoring the structural integrity of a supporting structure of a wind turbine, a wind turbine, and a computer program product for carrying out the steps of the inventive method.

A method is described for the early identification of material fatigue in drive train components of a wind turbine installation. In particular, a signal, representing revolutions per minute of a wind turbine shaft, is obtained and modulated by the azimuth angle measurement of the turbine blade. This signal is band passed at twice the frequency of rotation and Fourier transformed to extract amplitude values. An alert response can then be triggered when it is determined that there has been a change in a characteristic of the amplitude values such as the amplitude values increasing beyond a multiple of a determined baseline amplitude value.

A load mitigation arrangement of a non-mounted rotor blade, includes at least one actuatable lift-modification device arranged on a surface of the rotor blade; a monitor configured to estimate the magnitudes of loads acting on the non-mounted rotor blade; a controller configured to actuate the lift-modification device on the basis of the estimated magnitudes to mitigate the loads acting on the non-mounted rotor blade. Further provided is a rotor blade assembly, and a method of performing load mitigation on a non-mounted rotor blade.

A wind power generation device control system includes: a blade wind detecting device for detecting at least one of a wind direction or a wind speed on at least one blade of a wind power generation device; and a blade control device for controlling at least one of (i) a pitch angle of the at least one blade or (ii) a yaw angle of the wind power generation device, based on at least one of the wind direction or the wind speed detected by the blade wind detecting device.

A load sensor calibration method and apparatus, and a computer-readable storage medium are provided. The load sensor calibration method includes: acquiring operation data of a wind turbine generator set, wherein the operation data comprises data of the wind turbine generator set operating in a normal operating state or data of the wind turbine generator set operating under different predetermined pitch angle idling states; generating a calibration training set on the basis of the operation data; and calibrating a load sensor according to the calibration training set.

A method is for operating a wind turbine. The wind turbine includes a nacelle including a nacelle component, in particular a rotor bearing, and a nacelle air flow influencing unit. The nacelle air flow influencing unit is configured to influence an air flow entering, flowing through and/or exiting the nacelle. The method includes: determining an operating condition of the nacelle component, determining a cooling demand of the nacelle component dependent on the determined operating condition of the nacelle component, controlling an operation of the nacelle air flow influencing unit dependent on the cooling demand of the nacelle component to adapt the air flow to the cooling demand of the nacelle component.

The present disclosure is related to methods (400; 500; 600) configured for detecting the state of a wind turbine blade (22). The methods (400; 500; 600) comprising receiving (401; 501) load signals from a wind turbine blade (22), determining (402; 503) an energy of the load signal in a first and second frequency and comparing (403; 504) said energy to generate a flag signal if the energy in the first frequency is smaller than the energy in the second frequency. A control system (600) suitable to detect the state of a wind turbine blade (22) is also provided, as well as wind turbines (10) including such a control system (600).

Turbines, including fluid driven turbines, including wind turbines, do not always operate to their maximum capability due to sub-optimal selection of various possible parameters. Therefore there is industrial advantage in systems which can calculate, adjust or constrain such parameters in order to improve the productivity of turbines. New data also allows for new control methodologies. Such systems may be established through the provision of relevant data. The overall productivity of turbines may be improved, or increased, by extending the lifetime of the turbine, or by increasing the average power output during its lifetime, or reducing maintenance costs. One particular example of turbine under-performance has been observed by the present author for wind turbines operating in hilly terrain such as frequently found on Scottish wind farms but also in many locations around the world. Hilly terrain, or complex terrain, results in complex wind flow and energy production losses when control systems are not best designed to handle such flow. Although complex flow may arise for other reasons, such as complex weather or storms (both onshore and offshore), the complex flow due to complex terrain is always present for many turbines and therefore impacts productivity throughout their operational lifetime. Complex fluid flow data may be measured by instruments including converging beam Doppler LIDAR which is especially advantageous in providing three-dimensional fluid velocity data. Therefore the provision of data allows for control parameter adjustment to account for operational variables including fluid characteristics. Therefore the control parameters may be adjusted in order to better control a turbine for its local conditions. This allows for greater generation of renewable energy. Derivations thereof may also be applied to improve operational parameters of vehicles, including vehicles incorporating a rotor, as well as aircraft and spacecraft launching or operating within a fluid. This offers better vehicle control and improved safety.

A method for determining an estimated life of a mechanical device includes (1) acquiring a load spectrum of the mechanical device within a predetermined time range; (2) acquiring a lubricant state of the mechanical device within the predetermined time range; (3) determining a plurality of operating states experienced by the mechanical device within the predetermined time range based on the acquired load spectrum and the acquired lubricant state, and (4) determining an estimated life of the mechanical device based on the plurality of operating states of the mechanical device within the predetermined time range. Each operating state corresponds to a particular range of load values in the load spectrum and a particular degree of contamination in the lubricant state. The method may also determine the remaining useful life of a mechanical device. The method may be implemented in a device for determining the estimated life of a mechanical device.