A wind turbine has a Lidar device to sense wind conditions upstream of the wind turbine. Wind speed signals from the wind turbine are processed to detect an extreme operating gust. The detection is performed by differentiating the axial wind velocity and filtering for a period of time. On detection of extreme operating gust the system controller takes necessary evasive action which may include shutting down the turbine or varying the blade pitch angle.

A method for protecting a wind turbine from an extreme change in wind direction includes receiving a wind direction and/or a wind speed at the wind turbine. When a change in the wind direction or the wind speed exceeds a predetermined threshold, the method includes determining a margin to stall and/or zero lift of the at least one rotor blade of the wind turbine as a function of an angle of attack or change in the angle of attack at a blade span location of at least one rotor blade of the wind turbine. The method also includes implementing a corrective action for the wind turbine (without shutting down the wind turbine) when the margin to stall and/or zero lift exceeds a predetermined value so as to avoid stall and/or negative lift on the at least one rotor blade during operation of the wind turbine.

The invention is a method for controlling and/or monitoring a wind turbine 1 equipped with a LIDAR sensor 2. Control and/or monitoring provides an estimation of the wind speed at the rotor obtained an estimator and a LIDAR sensor 2. The estimator of the wind speed at the rotor is constructed from a representation of the wind, a model of the LIDAR sensor and a model of wind propagation.

Provided is a method of controlling at least one wind turbine in case of a rotational overspeed situation, the method including: determining a current state related to the wind turbine; providing data related to the current state as input to a turbine model; predicting a load of at least one wind turbine component and power output of the wind turbine using the turbine model provided with the input for plural control strategies; comparing the predicted load and power output for the plural control strategies; and selecting that control strategy among the plural control strategies that satisfies a target criterion including the load and the power output.

Provided is a structural health monitoring system of a rotating object such as a turbine blade, which gives easy and intuitive information to field managers on the damage location and the damage size of the rotating object by computing and visualizing correlations between damage and propagating ultrasonic wave. The structural health monitoring system for a rotating object comprises an ultrasonic generation system which generates an ultrasonic signal by irradiating a pulse laser beam to a point of the rotating object, a pulse laser control system which adjusts the irradiating time of the pulse laser beam, an ultrasonic measurement system which measures a generated ultrasonic signal at a point of the rotating object away from the point irradiated by the pulse laser beam and a damage detection system which provides information of damage existence, damage location and damage severity by visualization of monitored ultrasonic signals.

An apparatus and method is disclosed for over-rating a wind turbine using turbulence prediction. Weather forecast information is used to determine whether there is a risk of turbulent conditions occurring at the site of the wind turbine. The wind turbine is over-rated if turbulent conditions are not predicted, and conversely over-rating is cancelled or reduced if turbulent conditions are expected. This allows an increase in the annual energy production of the wind turbine to be realised. The weather forecast information may be combined with real time measurements of operating conditions to supplement the predictions.

Method of operating a wind turbine comprising a plurality of blades rotatable along their longitudinal axes using a pitch mechanism, and comprising one or more movable trailing edge surfaces. The method includes predicting, at a first moment in time, a high load for one or more of the blades at a second moment in time. The method further comprises actuating on one or more of the movable trailing edge surfaces of these blades such that the trailing edge surfaces have a wider range of control to counteract the predicted high loads before the second moment in time, and simultaneously pitching the blades such as not to negatively affect the operation of the wind turbine. The method furthermore comprises, at the second moment in time, actuating the one or more movable trailing edge surfaces of the at least one or more blades to counteract the high loads.

Controlling a wind turbine including measuring a wind speed for a location upwind of a wind turbine. Using the measured wind speed, a changed steady-state deflection of a structure of the wind turbine is predicted. The predicted changed steady-state deflection corresponds to a time when wind from the location is incident on the wind turbine. Oscillations of the structure are damped relative to the changed steady-state deflection. By damping the oscillations relative to the changed steady-state deflection, movements of the structure may be minimized when there is no predicted change in steady-state deflection, while permitting more rapid movements during transitions from one steady-state deflection to the predicted steady-state deflection, allowing more of the available power to be captured by the wind turbine.

The present subject matter is directed to a system and method for sequencing Light Detecting and Ranging (LIDAR) sensor beam signals from a LIDAR sensor mounted on a nacelle of a wind turbine with the rotor position of the wind turbine so as to improve signal availability. More specifically, the method includes generating, via the LIDAR sensor, one or more laser signals towards the rotor of the wind turbine, the rotor having one or more rotor blades. The method also includes receiving, via a controller, a rotor position of the rotor of the wind turbine. Thus, the method further includes coordinating, via a control algorithm programmed within the controller, the rotor position with the one or more laser signals of the laser sensor so as to minimize interference between the laser signal(s) and the rotor blades during rotation of the rotor.

The invention relates to a method of determining the vertical profile of the wind speed upstream from a wind turbine (1), wherein wind speed measurements are performed by a LiDAR sensor (2), then the exponent α of the power law is determined by an unscented Kalman filter and measurements, and the exponent α is applied to the power law in order to determine the vertical wind speed profile.