A method for protecting a wind turbine from extreme and fatigue loads associated with high wind speed events includes receiving, via a wind turbine condition estimator programmed in a turbine controller of the wind turbine, operating data indicative of current wind turbine operation. Further, the method includes determining, via the wind turbine condition estimator, a plurality of estimated wind turbine conditions at the wind turbine by solving a control algorithm having one or more equations using the operating data. The estimated wind turbine conditions include, at least, an estimated wind speed at the wind turbine and a loading proxy of the wind turbine. As such, the method includes implementing, via the turbine controller, a corrective action only when each of the estimated wind turbine conditions indicates that one or more loading conditions of the wind turbine exceeds a predetermined limit.

A method and a system for controlling a wind turbine based on sectors. Original sectors of the wind turbine are reconstructed based on a wind resource parameter and a wake-flow effect. A load is calculated and superposed for a new sector obtained from the sector reconstruction. An optimization algorithm is applied, under a condition that a constraint condition of a fatigue load is met, to find an operation parameter for maximum power generation amount of the wind turbine.

This document discloses a solution for analysing cavitation in a hydro turbine of a hydroelectric power plant. According to an aspect, a method comprises: measuring, by using at least one motion sensor coupled to a rotor of the hydro turbine, motion of the rotor during operation of the hydro turbine and thereby generating measurement data; acquiring, by at least one processor, the measurement data and one or more operational parameters of the hydro turbine employed during said measuring, the one or more operational parameters indicative of power supply of the hydro turbine; computing, by the at least one processor on the basis of the measurement data and the operational parameters, at least one metric indicative of an effect of the cavitation on the hydro turbine; comparing, by the at least one processor, the at least one metric with at least one threshold and determining, on the basis of the comparison, that the effect of the cavitation is too high; and outputting, by the at least one processor on the basis of said determining, information indicating unsuitability of the one or more operational parameters.

The present application discloses novel systems and methods for yawing an autonomous wind turbine. In an embodiment, the wind turbine includes a control system configured to determine a control action signal for a yaw drive mechanism of the wind turbine as a function of the wind condition(s) and as a function of the load condition(s). The control system is configured to monitor change(s) associated with the load condition(s) to determine if the load condition(s) is too high for too long, or in need of attention, before yawing of the wind turbine is initiated or, if the load condition(s) are getting too high, after yawing has been initiated. In another embodiment, the control system includes a load sensor system with proximity sensors arranged adjacent, on, and/or about the main shaft flange of the nacelle or on the rotor blades of the wind turbine.

A method for detecting and controlling whirling oscillations of the blades of a wind turbine is presented. The detection of the whirling oscillations is based on measurement signal indicative of blade oscillations, and a rotation transformation of the measurement signal from a measurement frame into at least one target frame based on the whirling oscillation frequency. The rotation-transformation comprises a backward or forward rotation transformation direction relative to a rotor rotation direction. The control is based on an oscillation component obtained from the rotation-transformed measurement signal where the oscillation component is indicative of the whirling oscillation in the backward and/or forward rotation direction.

Techniques for controlling the yaw of a wind turbine system by controlling a plurality of yaw drive actuators.

When the yaw drive actuators are applying the same torque to all the motors, this can lead to some motors overspeeding, if the motor is not engaged when the yaw system is activated.

Therefore, if the actual motor speed reference of a yaw drive actuator is higher than a specific motor speed reference, then an output signal to reduce the actual motor speed reference is applied to the yaw drive actuators with an actual motor speed reference higher than the specific motor speed reference.

A monitoring system for monitoring a time period of a locking state of a rotor of a wind turbine includes at least one motion sensor and at least one computing unit, wherein the computing unit is confiugered to receive at least one motion measurement from the at least one motion sensor and wherein the computing unit is configured to determine whether the rotor may remain in the locking state or the rotor should be unlocked based on the at least one motion measurement. A wind turbine having the monitoring system and a method for monitoring a time period of locking state of a rotor of a wind turbine is also provided.

A method and a system for controlling a wind turbine based on sectors. Original sectors of the wind turbine are reconstructed based on a wind resource parameter and a wake-flow effect. A load is calculated and superposed for a new sector obtained from the sector reconstruction. An optimization algorithm is applied, under a condition that a constraint condition of a fatigue load is met, to find an operation parameter for maximum power generation amount of the wind turbine.

A method is disclosed for controlling a wind turbine, where the wind turbine includes with a tower and a rotor and comprises having at least one rotor blade with an adjustable blade pitch angle, and where a change in a power value takes place in a time interval (TE) and by the control of one or more operating parameters which determine power to be fed in by the wind turbine. The method comprises determining a parameterized time function of a tower deflection for the time interval (TE). A series of boundary conditions are defined for the parameterized time function of the tower deflection and a thrust of the rotor of the wind turbine is determined for the parameterized time function of the tower deflection. A function is then calculated for controlling the one or more operating parameters from the thrust of the rotor.

Adjustment and/or drive units that can be used in wind turbines to set the azimuth angle of the wind turbine nacelle or the pitch angle of the rotor blades, wherein such an adjustment and/or drive unit has at least two actuating drives for rotating two assemblies, which are mounted for rotation relative to each other, and has a control device for controlling the actuating drives, which control device controls the actuating drives in such a way that the actuating drives are braced in relation to each other during the rotation of the two assemblies and/or at a standstill of the assemblies. The invention further relates to a wind turbine having such an adjustment and/or drive unit and to a method for controlling such an adjustment and/or drive unit.