Abstract: A method for controlling yawing of a wind turbine, wherein an efficiency information is determined based on previous yaw activities, wherein the efficiency information reflects a relationship between an effective angular change between at least two yaw positions of the previous yaw activities, and a corresponding accumulated angular movement between the at least two yaw positions, wherein the yawing is controlled based on the determined efficiency information is provided. Further, a wind turbine and a device as well as a computer program product and a computer readable medium are suggested for performing the method is also provided.

Abstract: Provided is a method of setting and clearing a full-power flag in a control process running on a wind turbine controller, the method including (a) acquiring a set of measured values and/or reference values for: rotor speed, output power, blade pitch angle, and activation level of an adaptive flow regulating system, (b) determining that a first condition is fulfilled when the value of the rotor speed equals a speed limit value and the output power reference value equals a power limit value, (c) determining when the blade pitch angle reference value fulfills a pitch condition and the activation level of the adaptive flow regulating system fulfills an adaptive flow regulating condition, or when the measured value of the rotor speed is below the speed limit value, (d) setting the full-power flag, and (e) clearing the full-power flag. Furthermore, a wind turbine controller and a wind turbine including such a controller.

Abstract: 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.

Abstract: Provided is a method of correcting a measurement value of least one wind characteristic, in particular wind speed and/or wind direction, related to a wind turbine having a rotor with plural rotor blades at least one having an adaptable flow regulating device installed, the method including: measuring a value of the wind characteristic; obtaining state information of the adaptable flow regulating device; and determining a corrected value of the wind characteristic based on the measured value of the wind characteristic and the state information of the adaptable flow regulating device.

Abstract: Provided is a device and a method of damping front and backward movements of a tower of a wind turbine, wherein the wind turbine includes the tower and a rotor, the rotor being mounted at the top of the tower to rotate about a rotational axis in which the front and backward movements of the tower occur, and the rotor has a plurality of blades, wherein each blade has at least one corresponding active add-on member which is actuated by a corresponding actuator to alter aerodynamic properties of the blade. Each add-on member is actuated by the corresponding actuator to alter the aerodynamic properties of the blade in a manner that the rotor is configured to damp the front and backward movements of the tower of the wind turbine.

Abstract: A method for controlling yawing of a wind turbine, wherein an efficiency information is determined based on previous yaw activities, wherein the efficiency information reflects a relationship between an effective angular change between at least two yaw positions of the previous yaw activities, and a corresponding accumulated angular movement between the at least two yaw positions, wherein the yawing is controlled based on the determined efficiency information is provided. Further, a wind turbine and a device as well as a computer program product and a computer readable medium are suggested for performing the method is also provided.

Abstract: A method is provided for operating a wind turbine, including the following steps: operating the wind turbine on a basis of a defined controller setting, operating the wind turbine on a basis of a first alternative controller setting, capturing a first performance information of the wind turbine operating according to the first alternative controller setting, operating the wind turbine on a basis of a second alternative controller setting, capturing a second performance information of the wind turbine operating according to the second alternative controller setting, and operating the wind turbine on a basis of the captured first and second performance information.

Abstract: A method and corresponding arrangement are provided for determining pitch angle adjustment signals for adjusting a pitch angle of a rotor blade connected to a rotation shaft of a wind turbine. The method includes obtaining a first maximal speed signal indicative of a first desired maximal rotational speed of the rotation shaft. The method also includes deriving a first pitch angle adjustment signal based on the first maximal speed signal. The method further includes obtaining a second maximal speed signal indicative of a second desired maximal rotational speed of the rotation shaft different from the first desired maximal rotational speed of the rotation shaft. Further, the method includes deriving a second pitch angle adjustment signal based on the second maximal speed signal. The second pitch angle adjustment signal is different from the first pitch angle adjustment signal.

Abstract: An automatic adjustment system for a variable-speed wind turbine is provided, having a power vector generator for generating a power vector (Pvec) of wind turbine output power; a mapping unit for establishing relationships (?vec, ?vec) between wind turbine output power and rotational speed and pitch angle on the basis of the power vector (Pvec) and an operational trajectory of the wind turbine; a wind speed estimator for estimating a wind speed (vest); an available power calculator for calculating the available power (Pest) of the wind turbine on the basis of the estimated wind speed (vest) and the established relationships (?vec, ?vec). A method of performing automatic analysis of a wind turbine configuration, a computer program product for carrying out the steps of such a method, and a wind turbine having such an automatic adjustment system are also provided.

Abstract: Provided is a method for performing a wind direction measurement for a wind turbine, the method including: measuring plural sample pairs, each pair including a measured relative wind direction and an associated performance quantity, the measured relative wind direction representing a measurement result of measuring a difference angle between a real wind direction and an orientation of a measurement equipment, in particular a direction orthogonal to a rotor blade plane, the performance quantity indicating a performance of the wind turbine; evaluating a degree of asymmetry of the performance quantity with respect to a measured relative wind direction equal to zero; measuring a further relative wind direction; and correcting the further measured relative wind direction based on the degree of asymmetry.

Abstract: A method of controlling a wind turbine having a rotor to which at least one rotor blade is connected, is provided herein. The method includes operating the rotor according to a first rotational speed reference; and operating the rotor according to a second rotational speed reference above the first rotational speed reference, if a fluctuation of an actual rotational speed of the rotor decreases below a fluctuation threshold and/or if a blade pitch angle of the rotor blade increases above a blade pitch angle threshold. The method may further include wherein the rotor is operated according to the first rotational speed reference, if the fluctuation of an actual rotational speed of the rotor increases above another fluctuation threshold which is above the fluctuation threshold and/or if the blade pitch angle of the rotor blade decreases below another blade pitch angle threshold which is below the blade pitch angle threshold.

Abstract: A method to control the operation of a wind turbine is provided. Wind-related values as well as these operating parameters of the wind turbine are measured: electrical output power, parameters of the rotating blade-system, accelerations and thrusts, which are impacting on wind turbine components. The measured values are used to generate respective time-based statistics. The statistics are used to estimate at least one of these loads: tower bending moment, blade bending moment and/or tower yawing moment. The estimated loads are compared with load threshold values, which are pre-determined for the given type of the wind turbine. The operation of the wind turbine is controlled in a way that, taking into account the load estimations, respective loads are reduced.

Abstract: A method and a control device for damping an oscillatory movement of the top of a tower of a wind turbine are provided. The described method includes (a) rotating a rotor being rotatably attached to a nacelle of the wind turbine with a rotational speed, and (b) yawing the nacelle of the wind turbine around an axis being aligned with the longitudinal axis of the tower with a yawing speed. Thereby, a yawing movement being associated with yawing the nacelle is coordinated with the oscillatory movement in such a manner that a gyroscopic torque resulting (i) from rotating the rotor and (ii) from yawing the rotor damps the oscillatory movement of the top of the tower. A wind turbine comprising such a control device and a computer program for controlling this method are also provided.

Abstract: A wind turbine rotor blade is equipped with an air chamber and equipped via the air chamber to route a modulation beam out of the rotor blade such that the air current along the rotor blade is changed. Thereby the laminar current is changed into a turbulent current on the one hand and its detachment and on the other hand its recreation is achieved in order to produce the laminar current. The control may occur via electrostatic actuators via a learnable control strategy based on neural forecasts, which take the complexity of the non-linear system into account and allow for the plurality of influencing factors. The stress on the rotor blades may be reduced, resulting in longer service life and reduced maintenance costs, a higher level of efficiency or quieter operation.

Abstract: A method to control the operation of a wind turbine above a wind speed threshold value and a wind turbine designed to execute the method are provided. Electrical output power of the wind turbine is produced by its rotating blades and fed into a grid, which is connected with the wind turbine. The wind turbine is controlled by a first control loop and a second control loop. The wind speed is determined and compared with a certain predefined wind speed threshold value. Wind turbulences are determined and compared with a predefined wind turbulence threshold value. The first control loop and the second control loop are activated when the wind speed reaches or exceeds the wind speed threshold value. The activated first control loop controls the output power dependent on the wind speed. The activated second control loop controls the rotational speed of the rotating blades dependent on the wind turbulences.

Abstract: A method for lubricating at least one blade pitch bearing of a wind turbine is provided. The wind turbine includes a rotor hub with a number of rotor blades, with each rotor blade being supported to the rotor hub by at least one blade pitch bearing. At least one rotor blade is pitchable and a rotor blade pitch control device adapted to control pitching of the at least one rotor blade. The state of lubrication of at least one blade pitch bearing by a lubrication detection device generating at least one lubrication information signal indicating a degree of lubrication of the at least one blade pitch bearing by measuring the electrical capacitance and/or resistance of the at least one blade pitch bearing. A rotor blade lubricating device is actuated to perform at least one action to lubricate the at least one blade pitch bearing, if the lubrication information signal indicates that the at least one blade pitch bearing is not sufficiently lubricated.

Abstract: A method of controlling a wind turbine having a rotor to which at least one rotor blade is connected, is provided herein. The method includes operating the rotor according to a first rotational speed reference; and operating the rotor according to a second rotational speed reference above the first rotational speed reference, if a fluctuation of an actual rotational speed of the rotor decreases below a fluctuation threshold and/or if a blade pitch angle of the rotor blade increases above a blade pitch angle threshold. The method may further include wherein the rotor is operated according to the first rotational speed reference, if the fluctuation of an actual rotational speed of the rotor increases above another fluctuation threshold which is above the fluctuation threshold and/or if the blade pitch angle of the rotor blade decreases below another blade pitch angle threshold which is below the blade pitch angle threshold.

Abstract: An automatic adjustment system for a variable-speed wind turbine is provided, having a power vector generator for generating a power vector (Pvec) of wind turbine output power; a mapping unit for establishing relationships (?vec, ?vec) between wind turbine output power and rotational speed and pitch angle on the basis of the power vector (Pvec) and an operational trajectory of the wind turbine; a wind speed estimator for estimating a wind speed (vest); an available power calculator for calculating the available power (Pest) of the wind turbine on the basis of the estimated wind speed (vest) and the established relationships (?vec, ?vec). A method of performing automatic analysis of a wind turbine configuration, a computer program product for carrying out the steps of such a method, and a wind turbine having such an automatic adjustment system are also provided.

Abstract: A method is provided for damping an oscillatory movement of a nacelle of a wind turbine. The nacelle is attached to a tower of the wind turbine. The method involves rotating the nacelle about a yawing axis with a yawing speed, the yawing axis being aligned with a longitudinal axis of the tower, changing the yawing speed, and coordinating the yawing speed with the oscillatory movement such that a torque resulting from the change of the yawing speed damps the oscillatory movement of the nacelle of the tower.

Abstract: A method for determining and applying a pitch angle offset signal for controlling a rotor frequency of a rotor of a wind turbine is disclosed. The method includes obtaining a motion quantity indicative of a motion of the rotor and determining the pitch angle offset signal based on the motion quantity such that the pitch angle offset signal is adapted to be used for adjusting a blade pitch angle of a rotor blade mounted at the rotor for controlling the rotor frequency in order to reduce a time span during which the rotor is in a critical motion region. A corresponding system and a method for controlling a rotor frequency are also disclosed.