Abstract: A method for reducing vibrations of a wind turbine includes a plurality of set points characterizing set values of operation parameters of the wind turbine. The method includes measuring an acceleration force value corresponding to acceleration forces acting on the turbine, and determining whether the measured acceleration force value is above a predetermined threshold value. Furthermore, in case it is determined that the acceleration force value is above the predetermined threshold value, the set point value of at least one set point of the plurality of set points is modified in order to reduce the vibrations in such a way that a power output of the wind turbine is not reduced.

Abstract: Described is a controller, wherein the controller is adapted: to control a transformation ratio of a park transformer of a wind turbine park including wind turbines connected to a first node. The park transformer is connected between a first node and a second node which is connected to a utility grid to which electric energy produced by the wind turbines is to be delivered. Further a wind park and a control method are described.

Abstract: A method for controlling a wind turbine with a rotor and at least one rotor blade, and a control unit are disclosed. The method is characterized in adjusting a pitch angle of the rotor blade and determining the limit of an input value based on the adjusted pitch angle, wherein the input value includes information about the turbine rotational speed.

Abstract: A method for acoustically monitoring a wind turbine, in particular for monitoring the existence of loose objects inside the wind turbine is provided. A sound generated in a rotating part of the wind turbine is monitored during operation of the wind turbine which sound is analyzed with respect to specific parameter values of the sound within at least one specific frequency range and if such specific parameter values are detected, a signal for possible further actions is generated. An acoustic monitoring system for a wind turbine and a re-equipment kit are also disclosed.

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: The disclosure concerns a method for operating a wind farm, the wind farm includes a wind turbine, and an energy storage device, the wind farm being connected to an external grid, the method comprising determining a demanded active power, determining a demanded reactive power, determining power production of the wind turbine, and charging the energy storage device, when the power production is above the demanded active power, the demanded reactive power, or the vector sum of demanded active power and demanded reactive power. Furthermore, corresponding wind farm controllers, wind farms, program elements, and computer readable media are subject of the current disclosure.

Abstract: A method for determining a mass change at a rotating blade of a wind turbine is provided. The method includes measuring a vibration quantity representative of a vibration of the wind turbine, measuring an azimuthal quantity representative of a rotation angle of the blade, determining a frequency quantity representative of a vibration frequency of the blade from the vibration quantity and the azimuthal quantity, and determining the mass change at the blade based on the frequency quantity.

Abstract: A method for detecting a rotor blade pitch angle adjustment fault of a rotor blade of a wind turbine is provided, the method includes measuring a rotor blade pitch angle speed; predicting, based on an actual rotor speed, a rotor blade pitch angle speed; indicating a fault, if a first criterion is satisfied, wherein the first criterion is satisfied, if deviation between the measured rotor blade pitch angle speed and the predicted rotor blade pitch angle speed exceeds a speed threshold.

Abstract: A method of operating a wind park having a plurality of wind turbines is provided. The method includes determining a grid condition indicator indicative of the condition of a grid into which the wind park feeds; determining a first maximum power value of the wind park on the basis of the grid condition indicator; determining an operating margin on the basis of the grid condition indicator, for a grid condition indicator indicative of a weak grid; determining a second maximum power value on the basis of the operating margin; and curtailing the active power output of the wind park according to a maximum power value. A computer program product for carrying out the steps of such a method; an active power controller adapted for use in operating a wind turbine of a wind park; a wind turbine; and a wind park are also provided.

Abstract: A reflector is arranged at a first position, which is assigned to a first end of the object. An antenna-system is arranged at a second position, which is assigned to a second end of the object. The antenna system contains a transmit antenna and a receive antenna, while the reflector and the antenna-system are coupled by a radio signal. The radio signal is sent from the transmit antenna via the reflector towards the receive antenna. The receive antenna is connected with an evaluation unit, which is prepared to measure the deflection between the first end of the object and the second end of the object based on the received radio signal.

Abstract: A method for estimating grid properties of a power grid coupled to a generator at a point of common coupling is provided. First, a voltage VPCC at the point of common coupling is measured. Second, a current IPCC at the point of common coupling is measured. Third, the grid properties are estimated by a grid model using as input parameters the measured voltage VPCC at the point of common coupling, the measured current IPCC at the point of common coupling and the determined phase angle. Advantageously, the absolute phases of the voltage and the current at the point of common coupling are not necessary, which makes the present method less prone to errors due to measurement noise. Further, a device and a computer program product are provided.

Abstract: A method for computer-assisted determination of usage of electrical energy produced by a power generation plant such as a renewable power generation plant is provided. The method uses a plurality of neural networks having a different structure or being learned differently for calculating future energy amounts produced by a power generation plant. To do so, the energy outputs of the power generation plant forecasted by the plurality of the neural networks are used to build histograms. Based on the histograms, energy amounts for different confidence levels describing the likelihood of the availability of the energy amount are determined, and different uses are assigned to different energy amounts. Energy amounts having a higher likelihood of availability in the future are sold at higher prices than other energy amounts.

Abstract: A method for controlling the operation of a wind farm with a plurality of wind turbines is disclosed A setpoint vector is defined, wherein each component of the setpoint vector represents an individual power setpoint of one of the plurality of wind turbines. A dependency matrix, which reflects a desired power generation distribution between different wind turbines of the plurality of wind turbines, is determined. A power reference vector is calculated by multiplying the dependency matrix with the setpoint vector, such that the power reference vector comprises a coordinated power setpoint for each wind turbine. The operation of the wind farm is controlled based on the calculated power reference vector. A superordinate control system, a wind farm, a computer-readable medium and a program element, which are adapted for performing and/or for controlling the above described wind farm operation control method are further disclosed.

Abstract: An arrangement to measure deflection of a blade of a wind turbine is provided. A transmitter is arranged close to the tip end of the blade, while a receiver is arranged close to the root end of the blade. The transmitter and receiver are prepared for a wireless transfer of a monitoring signal, which is sent from the transmitter to the receiver. A monitoring system is arranged close to the root end of the blade. The monitoring system is adapted to generate the monitoring signal. The monitoring system is connected with the transmitter by a cable-bound communication line, thus the monitoring signal is transferred from the monitoring system to the transmitter. The monitoring system is connected with the receiver, thus the monitoring signal is transferred from the receiver to the monitoring system. The monitoring system is adapted to determine the deflection of the blade based on the transferred monitoring signal.

Abstract: It is described a method for controlling the rotational speed of a rotor of a wind turbine in particular at high wind speeds. The described method comprises (a) determining a rotor acceleration value, wherein the rotor acceleration value is caused by a temporal change of the rotational speed of the rotor, and (b) controlling the rotational speed of the rotor as a function of the rotor acceleration value. It is further described a control system for controlling the rotational speed of a rotor of a wind turbine, a wind turbine being equipped with such a control system and to a computer program, which is adapted for controlling and/or for carrying out the mentioned rotational speed control method.

Abstract: A method for reducing vibrations of a wind turbine includes a plurality of set points characterizing set values of operation parameters of the wind turbine. The method includes measuring an acceleration force value corresponding to acceleration forces acting on the turbine, and determining whether the measured acceleration force value is above a predetermined threshold value. Furthermore, in case it is determined that the acceleration force value is above the predetermined threshold value, the set point value of at least one set point of the plurality of set points is modified in order to reduce the vibrations in such a way that a power output of the wind turbine is not reduced.

Abstract: A method for reducing vibrations of a wind turbine includes a plurality of set points characterizing set values of operation parameters of the wind turbine. The method includes measuring an acceleration force value corresponding to acceleration forces acting on the turbine, and determining whether the measured acceleration force value is above a predetermined threshold value. Furthermore, in case it is determined that the acceleration force value is above the predetermined threshold value, the set point value of at least one set point of the plurality of set points is modified in order to reduce the vibrations in such a way that a power output of the wind turbine is not reduced.

Abstract: Disclosed is a method of reducing a structural unbalance in a wind turbine rotor with pitch control and a control device for performing. A frequency component is detected resulting from the structural unbalance in the wind turbine rotor on the basis of the rotor speed signal. The multiplying the frequency component signal is multiplied by a complex correction factor. Individual pitch angle offsets are establishing for each blade of the rotor based on the magnitude and the phase and complex correction factor. Individual pitch angle offset are added to the respective pitch angles of the blades of the rotor.

Abstract: The disclosure relates to a method for controlling a wind farm, the wind farm includes at least two wind turbines, the method includes determining the required power, determining fatigue load versus power curves for each wind turbine, and based on the determined fatigue load versus power curves attributing different power settings to the wind turbines such that sum of the power settings of all wind turbines is equal to the required power. Furthermore, the invention concerns a park controller for controlling a wind farm and a program element for controlling a wind farm.

Abstract: In one aspect, a system for triggering an emergency system of a wind turbine is described. The system comprises a sensor for sensing an acceleration value of a portion of the rotor of the wind turbine, an estimation unit coupled to the sensor, wherein the estimation unit is adapted for receiving the acceleration value from the sensor and for estimating a rotor rotational speed value of the rotor of the wind turbine based on the acceleration value, and a triggering unit coupled to the estimation unit, wherein the triggering unit is adapted for receiving the rotor rotational speed value and for triggering the emergency system, when the rotor rotational speed value exceeds a predefined limit value. Further described are a method for triggering an emergency system of a wind turbine, a wind turbine, a computer program and a computer-readable medium, which are all adapted for carrying out the triggering method.