Patent application number | Description | Published |
20080247873 | Method of reducing a structural unbalance in a wind turbine rotor and device for performing the method - Disclosed is a method of reducing a structural unbalance in a wind turbine rotor with pitch control and a control device for performing the method are provided. The method comprises the steps of: detecting a magnitude of the structural unbalance and its phase in relation the rotor's azimuth (θ) on the basis of a measurement of the rotor's azimuth (θ) and a measurement of the rotor speed or the generator speed (ω), establishing individual pitch angle offsets for each blade of the rotor on the basis of the magnitude and the phase, and adding the individual pitch angle offsets to the respective pitch angles of the blades of the rotor. | 10-09-2008 |
20080298963 | Method and device for controlling load reduction for a wind turbine rotor - A method for controlling load reduction for a wind turbine rotor with rotor blades comprising an aerodynamic active element responsive to a control signal for modifying its setting is provided. The loads acting on the rotor blades in relation to the rotor's azimuth are detected and individual control signals based on a PI control system are established. Each individual control signal is a complex number containing an amplitude defining the degree of modification of the respective setting and an angle defining the phase of the modification of the respective setting with respect to the rotor's azimuth. The angle of the complex number is corrected by a phase correction factor. The elements are provided with the individual control signals. The input to the PI-control system is a complex load vector. | 12-04-2008 |
20090004009 | Method for controlling of at least one element of a first component of a wind turbine, control device and use of the control device - The invention concerns a method for controlling of at least one element of a first component of a wind turbine and a control device not permanently belonging to the wind turbine wherein the control device is connected to a communication interface of the first component for supporting the mounting of the first component and a second component of the wind turbine with each other and/or for the purpose of service of the wind turbine. Moreover the invention concerns the use of the control device for controlling of at least one element of a first component of a wind turbine during the mounting of the first component and a second component of the wind turbine with each other and/or during a service procedure of the wind turbine. | 01-01-2009 |
20090047130 | Wind Turbine and Method for Determining at Least One Rotation Parameter of a Wind Turbine Rotor - A method of determining at least one rotation parameter of a wind turbine rotor rotating with a rotation speed and a phase is provided. The method comprises the steps of: measuring an effective centrifugal force acting in a first pre-determined direction, which is defined in a co-ordinate system rotating synchronously with the rotor, on at least one reference object located in or at the rotor, establishing a first angular frequency representing the rotation speed of the rotor on the basis of variations in the measured effective centrifugal force due to gravitational force, establishing a second angular frequency representing the rotation speed of the rotor by use of at least one yaw rate gyro, and establishing the value of the rotation speed as the rotational parameter by correcting the second angular frequency by comparing it to the first angular frequency. | 02-19-2009 |
20090068013 | Wind turbine, yaw system controller and yaw system for a wind turbine and method of reducing the acting on such a yaw system - A method for reducing the loads acting on a wind turbine yaw system due to yawing moments which are induced to the yaw system by a rotor which comprises at least one rotor blade with a pitch control system is provided. In the method, the yawing moment which is induced to the yaw system by the rotor is determined and the pitch of the at least one rotor blade is set based on the detected yawing moment such that the determined yawing moment is reduced. | 03-12-2009 |
20090102198 | Method for controlling wind turbines, and devices therefore - Method for controlling the rotational speeds of wind turbines, including determining the rotor rotational speed of a first and a second wind turbine; determining the rotor azimuth angle of the first and the second wind turbine; calculating a speed control value for the first wind turbine, based on the determined rotor azimuth angles and rotor rotational speeds; adjusting the rotor rotational speed of the first wind turbine according to its speed control value, wherein the speed control value is calculated such that the rotor azimuth angle of the first wind turbine is equal to the rotor azimuth angle of the second wind turbine after speed adjustment, and a wind turbine control master unit, a wind turbine control slave unit, a wind turbine control device, a signal light control module, and a wind turbine therefor. | 04-23-2009 |
20090180875 | METHOD FOR DETERMINING FATIGUE LOAD OF A WIND TURBINE AND FOR FATIGUE LOAD CONTROL, AND WIND TURBINES THEREFOR - A method of determining fatigue load of at least one operative wind turbine, comprising: providing a transfer function that associates an obtained at least one measurement value of a first sensor to an obtained at least one measurement value of a second sensor the at least one measurement value of the first sensor and the at least one measurement value of the second sensor being obtained by use of a reference wind turbine at which the first sensor and the second sensor are located; obtaining at least one measurement value of a third sensor, wherein the third sensor is located at the at least one operative wind turbine, and wherein the third sensor corresponds in type and position to the first sensor at the reference wind turbine; calculating at least one transfer function value corresponding to the obtained at least one measurement value of the third sensor by use of the provided transfer function; calculating the fatigue load of the at least one operative wind turbine based on the calculated transfer function value. | 07-16-2009 |
20090230682 | Apparatus and method for determining a resonant frequency of a wind turbine tower - An apparatus for determining a resonant frequency of a wind turbine tower is provided. The apparatus includes a processing unit configured to receive an acceleration measurement value, the acceleration measurement value representative of the acceleration of the wind turbine tower in the direction parallel to a rotor rotational axis of the wind turbine and/or in the direction perpendicular to both the rotor rotational axis and the tower axis of the wind turbine. The apparatus includes a memory configured to store a series of acceleration measurement values, and the processing unit includes a Fourier transform module configured to calculate a spectral vector based on calculating a convolution-based fast Fourier transform of the series of acceleration measurement values, and includes a resonant frequency calculation module configured to calculate the tower resonant frequency based on the calculated spectral vector. | 09-17-2009 |
20090250932 | Method of damping tower vibrations of a wind turbine and control system for wind turbines - A control system for a wind turbine is provided. A pitch-control unit establishes a pitch-reference signal representing a pitch to be set by the pitch-actuator system. A rotor-speed input receives a signal representing a speed of the rotor. A speed-reference input receives a speed-reference signal for the rotor speed. An inclination-signal input receives a signal representing a tower inclination. A pitch-reference output outputs the pitch reference signal. A modification unit is connected to the speed-reference input to receive the speed-reference signal and connected to the inclination-signal input to receive the inclination signal. The modification unit establishes a modification signal based on the inclination signal, to modify the speed-reference signal via the modification signal, and to output a modified-speed-reference signal. The pitch-control unit connected to the modification unit to receive the modified-speed-reference signal and establish the pitch-reference value at least based on the difference between the modified-speed-reference and the rotor-speed signals. | 10-08-2009 |
20090257873 | Method and apparatus for prediction-based wind turbine control - A method an apparatus of automatically controlling a wind turbine re provided. of: A time-series of measurement values of the aerodynamic flow property of the wind turbine rotor blade is determined; a predictive wind field model representing a structure of a wind field acting on the wind turbine rotor blade is generated based on the time-series of measurement values, and a control value is generated based on the wind-field model. | 10-15-2009 |
20090292397 | METHOD AND APPARATUS FOR DAMPING TOWER OSCILLATION IN A WIND TURBINE - A method of damping tower oscillation in a wind turbine is provided. The method includes the steps of determining a rotor rotational speed of the wind turbine and controlling the rotor rotational speed such that a critical rotor speed is avoided, characterized in that it further comprises the following steps: selecting at least one input parameter value; selecting, according to the input parameter value, an operation mode for controlling the rotor rotational speed, wherein the operation mode is selected from a set of modes comprising a mode of auto tune operation; on the condition of the selected operation mode comprising the mode of auto tune operation, performing the following steps: detecting the tower oscillation frequency; calculating the critical rotor speed based on the detected tower oscillation frequency and controlling the rotor rotational speed to avoid the calculated critical rotor speed. An apparatus and a computer program product are also provided. | 11-26-2009 |
20100013235 | METHOD AND ARRANGEMENT FOR DAMPING OF TOWER-OSCILLATIONS - A method and an arrangement for the damping of tower-oscillations are provided. The method for the damping of tower-oscillations includes transforming a rotation into electrical power using a generator, which is located on top of the tower. The electrical power is transformed from AC to DC and back to AC by a converter. A power-reference-signal is used by the converter to control the delivered electrical power. A variable power-offset-signal is added to the power-reference-signal before it is used for the control. The variable power-offset-signal is based on a mean value of the power-reference-signal and a side-to-side-oscillation of the tower. | 01-21-2010 |
20100063769 | METHOD FOR THE DETERMINATION OF A NACELLE-INCLINATION - In one aspect, a method for the determination of a nacelle-inclination is provided. A first difference-signal is formed from the difference of a measured nacelle acceleration and an offset-value from a calibration. A second difference-signal is formed from a difference of the first difference-signal and a feedback signal. A first sum-signal is formed from adding an integrated second difference-signal with the product of the second difference signal and a factor. A second sum signal is formed from adding an integrated first sum-signal with the product of the first-sum-signal and the factor. A corrected signal is formed by a product of the second sum-signal and an equivalent tower height. A first nacelle-signal is formed by the arc-tangent of the corrected signal. A nacelle inclination is obtained from filtering the first nacelle-signal by a low-pass-filter. The feedback-signal is formed by multiplying the acceleration of gravity with the sine of the first nacelle-signal. | 03-11-2010 |
20100090464 | ADAPTIVE ADJUSTMENT OF THE BLADE PITCH ANGLE OF A WIND TURBINE - It is described a method of determining a quality of an initial value for a blade pitch angle. An initial power captured by a wind turbine is measured, while the blade pitch angle has the initial value. The blade pitch angle is changed from the initial value to a first value in a first direction. A first power captured by the wind turbine is measured and the blade pitch angle is changed to a second value in a second direction being opposite to the first direction. Further, a second power captured by the wind turbine is measured, a power difference between the first power and the second power is calculated, and the quality of the initial value based on the calculated power difference is determined. Further, a control system, a wind turbine and a computer program are described. | 04-15-2010 |
20100127495 | ESTIMATING AN ACHIEVABLE POWER PRODUCTION OF A WIND TURBINE BY MEANS OF A NEURAL NETWORK - A method for estimating an achievable power production of a wind turbine, which is operated with a reduced power set point is provided. The method includes determining the values of at least two parameters, inputting the values of the at least two parameters into a neural network, and outputting an output value from the neural network. The at least two parameters are indicative of an operating condition of the wind turbine. Thereby, the output value is an estimate of the achievable power production of the wind turbine. A control system which is adapted to carry out the described power estimation method is also provided. Furthermore, a wind turbine which uses the control system adapted to carry out the described power estimation method is provided. | 05-27-2010 |
20100140941 | CONTROL OF THE ROTATIONAL SPEED OF A WIND TURBINE WHICH IS IMPEDED TO EXPORT ELECTRICAL POWER TO AN ELECTRICITY NETWORK - A rotational speed controlling device for a wind turbine is provided. The controlling device includes a first input node for receiving a first signal, indicative of an actual rotational speed of the rotor, a second input node for receiving a second signal, indicative of a reference rotational speed for the rotor, a detection unit for detecting a defective operational state in which the wind turbine is impeded to export electrical power to an electricity network, a control unit for providing a reference signal for a characteristic operational parameter of the wind turbine based on the first signal and the second signal, and a pulse generator adapted to send a kick pulse to an integral control element of the control unit in response to the detection of the defective operational state. The characteristic operational parameter is indicative of the rotational speed of the rotor. | 06-10-2010 |
20100143093 | ARRANGEMENT TO DETECT A HIGH ROTATIONAL-SPEED OF A BLADE - An arrangement for determining a rotational-speed of a blade rotating around an axis is provided. A transmit-unit is located at the rotating blade, while a receive-unit is located at the rotating hub of the blade. The transmit-unit and the receive-unit are connected by a transmission-system, which is used to transmit a signal from the transmit-unit to the receive-unit. A detection-unit is located at the blade, which is used to detect a force acting on the blade due to the rotation of the blade. The detection-unit is built to interrupt the transmission of the signal when the detected force exceeds a predetermined value. The receive-unit comprises a control-unit, which detects a high rotational-speed of the blade by evaluating the interrupted transmission of the signal. The transmission-system is built as an optical-transmission system, which transmits an optical-signal from the transmit-unit to the receive-unit for evaluation. | 06-10-2010 |
20100209243 | Monitoring of Blade Frequencies of a Wind Turbine - A method for monitoring blade frequencies of a wind turbine and a monitoring system for performing the method are provided. An accelerometer or G-sensor is placed into a nacelle of a wind turbine and thereby measuring the vibrations of the nacelle. To extract the vibration signals originating from each blade, the vibration signals are combined with the measuring signals from the azimuth angle sensor (rotating angle), which is normally used for pitch control. To further extract each blade frequency a Fast Fourier Transformation is used on the modulated G-sensor signals. To further monitor a severe and alarming change in each blade frequency, each blade frequency is compared to the other blade frequencies and an alarm is set when a given level is reached. | 08-19-2010 |
20100319336 | Leakage Detection System in a Wind Turbine - In one aspect, a hydraulic system including a reservoir, a hydraulic device, a first sensor, a second sensor and a controller is described. The reservoir is connected to the hydraulic device for supplying hydraulic fluid to and from the hydraulic device. The first sensor is adapted for measuring a first volume of the hydraulic fluid in the reservoir. The second sensor is connected to the hydraulic device such that at least one parameter being indicative for a second volume of the hydraulic fluid in the hydraulic device is measurable. The controller is adapted for calculating the second volume of the hydraulic fluid based on the at least one parameter. The controller is adapted for determining a leakage of hydraulic fluid in the hydraulic system based on the first volume and the second volume. | 12-23-2010 |
20110006525 | Method for Operating a Wind Farm Comprising a Plurality of Wind Turbines - A method and a device for operating a wind farm with a plurality of wind turbines are provided. According to the method, operating parameters of the wind turbines of the wind farm are adjusted according to an optimization goal, the optimization goal being the maximum value of the total output of the wind farm produced from the sum of all individual outputs of the wind turbines. The optimization goal differs from conventional optimization goals where the respective individual outputs of the wind turbines are optimized without taking the overall output into consideration. | 01-13-2011 |
20110148110 | Monitoring of blade frequencies of a wind turbine - A method for monitoring blade frequencies of a wind turbine and a monitoring system are provided. An accelerometer is attached to a rotating hub of a wind turbine measuring vibrations of the hub. To extract vibration signals originating from each blade, the vibration signals are combined with measuring signals from the azimuth angle sensor. Alternatively, the azimuth angle is found by using the measured accelerations in two directions representing the centrifugal forces and vibrating forces of the hub and feeding these signals into a phase locked loop unit establishing a phase of the rotating hub representing the azimuth angle. To extract each blade frequency, a Fast Fourier Transformation is used on the signals from the accelerometer. To monitor a severe change in each blade frequency, each blade frequency is compared to other blade frequencies and an alarm is set when a given level is reached and the wind turbine is stopped. | 06-23-2011 |
20110150648 | BLADE DEFLECTION MEASUREMENT WITH MAGNETOSTRICTIVE SENSOR - A measurement arrangement for measuring a deflection of a wind turbine rotor blade is provided. The measurement arrangement includes a magnetostrictive sensor, which includes a first sensor part and a second sensor part, a first support structure, which is adapted to be mounted to a first portion of the rotor, wherein the first sensor part is mounted to the first support structure, and a second support structure, which may be mounted to a second portion of the rotor, wherein the second sensor part is mounted to the second support structure and wherein either or both the first portion and the second portion is a portion of the blade. The magnetostrictive sensor measures the relative spatial position between the first sensor part and the second sensor part. A method for measuring a blade deflection and a wind turbine rotor which includes the described blade deflection measurement arrangement are also provided. | 06-23-2011 |
20110153097 | SYSTEM FOR TRIGGERING AN EMERGENCY SYSTEM OF A WIND TURBINE - 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. | 06-23-2011 |
20110175353 | Wind farm power control based on matrix reflecting a power load distribution between individual wind turbines - 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. | 07-21-2011 |
20110210552 | Asynchronous Power Generator for a Wind Turbine - An asynchronous power generator for a wind turbine is provided. The asynchronous power generator includes a voltage supply and a stator with stator coils supplied with an alternating voltage by the voltage supply. The voltage supply is configured to adjust the voltage supplied to the stator coils based upon an output power generated by the wind turbine. Further, a method of voltage control is provided. | 09-01-2011 |
20110221194 | Rotational Speed Control of a Wind Turbine Based on Rotor Acceleration - 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. | 09-15-2011 |
20110313591 | Method and system for controlling a power production entity - A method for controlling a power production entity is provided. The method includes generating a plurality of electric power signals by a plurality of power production entities, measuring a plurality of power levels of the plurality of power signals, modifying the plurality of power signals, supplying the plurality of modified power signals at a common node, and adjusting an operation voltage of at least one power production entity of the plurality of power production entities based on the plurality of measured power levels such that a power loss of the power signals caused by the modifying and/or supplying is minimized. Also a system for controlling a power production entity is described. | 12-22-2011 |
20120042727 | Wind Turbine and Method of Determining at Least One Rotation Parameter of a Wind Turbine Rotor - A method of determining at least one rotation parameter of a wind turbine rotor rotating with a rotation speed and a phase is provided. The method includes: measuring an effective centrifugal force acting in a first pre-determined direction, which is defined in a co-ordinate system rotating synchronously with the rotor, on at least one reference object located in or at the rotor, establishing a first angular frequency representing the rotation speed of the rotor on the basis of variations in the measured effective centrifugal force due to gravitational force, establishing a second angular frequency representing the rotation speed of the rotor by use of at least one yaw rate gyro, and establishing the value of the rotation speed as the rotational parameter by correcting the second angular frequency by comparing it to the first angular frequency. | 02-23-2012 |
20120091713 | Method and system for adjusting a power parameter of a wind turbine - A method for adjusting a power parameter of a wind turbine is disclosed. The method includes determining a load parameter indicative of a mechanical load of the wind turbine; estimating a turbulence of a wind speed based on the determined load parameter; and adjusting the power parameter relating to a power of the wind turbine based on the estimated turbulence. A system for adjusting a power parameter of a wind turbine is also described. | 04-19-2012 |
20120133139 | Method for controlling wind turbines, and devices therefore - A wind turbine control master unit has a communication interface and a signal processing unit. The communication interface is configured to receive a rotor rotational speed of at least a first and a second wind turbine over a communication link. The signal processing unit is configured to determine a synchronized rotor speed value based on a mean value of the rotor rotational speeds. The signal processing unit is configured to calculate a synchronized azimuth angle value based on integrating the synchronized rotor speed value. Further, the communication interface is configured to send the synchronized rotor speed value and the synchronized azimuth angle value over a communication link. Also, a signal light control module and a wind turbine in connection with the control master unit are provided. | 05-31-2012 |
20120146331 | METHOD FOR REDUCING VIBRATIONS OF A WIND TURBINE AND CONTROL SYSTEM FOR REDUCING VIBRATIONS - 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. | 06-14-2012 |
20120186343 | Method for balancing a rotor mounted on a hub of a wind turbine - It is described a method for balancing a rotor mounted on a hub of a wind turbine. The method includes measuring a parameter value of a parameter being indicative of the revolution frequency components of the rotor and/or of a generator of the wind turbine during operation of the wind turbine, calculating a change of the spatial mass distribution of the rotor based on the parameter value of the parameter, which change is needed for balancing the rotor, and balancing the spatial mass distribution of the rotor by using at least one balancing weight element being attachable to at least one blade of the rotor based on the calculated change of the spatial mass distribution. It is further described a system for balancing a rotor, a wind turbine, a computer program and a computer-readable medium, which are all adapted for carrying out the above described balancing method. | 07-26-2012 |
20120200444 | Arrangement to measure the deflection of an object - 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. | 08-09-2012 |
20120257967 | METHOD AND CONTROLLER FOR GENERATING A BLADE PITCH ANGLE CONTROL SIGNAL AND WIND TURBINE COMPRISING THE CONTROLLER - A method for generating a blade pitch angle control signal for controlling a blade pitch angle of a rotating rotor blade for damping a rotor blade vibration, in particular an edgewise rotor blade vibration, of the rotating rotor blade is disclosed. The blade pitch angle control signal is generated such that it varies in accordance with a rotor blade vibration motion. A controller and a wind turbine are also disclosed. | 10-11-2012 |
20120261917 | Black Start of Wind Turbine Devices - A wind turbine device having in one embodiment a diesel generator to initialize a black start in case of a blackout of an electricity network is disclosed. For performing the black start, the diesel generator provides a predetermined voltage to a power output of the wind turbine device in order to imitate the electricity network in its running state. A wind park is also disclosed, the wind park having in one embodiment at least two wind turbine devices. In one embodiment a wind park controller provides the same reference value for the phase angle φ for the at least two turbines. | 10-18-2012 |
20120321464 | Method for acoustically monitoring a wind turbine, acoustic monitoring system for a wind turbine and re-equipment kit - 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. | 12-20-2012 |
20130002211 | CONTROLLER, WIND PARK AND CONTROL METHOD - 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. | 01-03-2013 |
20130022464 | Control of a wind turbine, rotor blade and wind turbine - 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. | 01-24-2013 |
20130031966 | METHOD AND SYSTEM FOR DETERMINING A MASS CHANGE AT A ROTATING BLADE OF A WIND TURBINE - 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. | 02-07-2013 |
20130125632 | DETERMINING AN ACCUMULATED LOAD OF A WIND TURBINE IN ANGULAR SECTORS - A method for determining a total mechanical load of a wind turbine is provided. A present load signal indicative of a present load of a wind turbine base structure is obtained, wherein the present load acts in a present angular direction. A first present load and a second present load are derived based upon the present load signal and the present angular direction, wherein the first present load is associated with a first angular sector of the turbine and the second present load is associated with a second angular sector of the turbine. Further, a total mechanical load is derived based upon the first present load and the second present load. | 05-23-2013 |
20130131879 | ARRANGEMENT FOR GENERATING A CONTROL SIGNAL FOR CONTROLLING A POWER OUTPUT OF A POWER GENERATION SYSTEM - An arrangement for generating a control signal for controlling a power output of a power generation system is described. The power output is to be supplied to a utility grid, the arrangement includes an input terminal for receiving an input signal indicative of an actual grid frequency of the utility grid; a control circuit for generating the control signal wherein the control circuit comprises a first circuit for generating a time derivative value of the input signal; and an output terminal to which the control signal is supplied, wherein the control signal depends on the generated time derivative value of the input signal. Further a power generation system is described. | 05-23-2013 |
20130161949 | METHOD, PARK CONTROLLER AND PROGRAM ELEMENT FOR CONTROLLING A WIND FARM - 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. | 06-27-2013 |
20130161952 | Method for controlling a wind turbine - 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 characterised 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. | 06-27-2013 |
20130204447 | WIND TURBINE WITH PRICE-OPTIMISED TURBINE LOAD CONTROL - A method of controlling the load of a wind turbine is provided. A rate of wear experienced by the wind turbine as a result of the current operating conditions of the wind turbine is determined. A control vector for controlling the wind turbine is determined based on the determined rate of wear. The load of the wind turbine is controlled in accordance with the determined control vector. Determining the control vector includes weighting the determined rate of wear by a cost of electricity value and determining the control vector based on the weighted rate of wear. | 08-08-2013 |
20130249215 | METHOD FOR OPERATING A WIND FARM, WIND FARM CONTROLLER AND WIND FARM - 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. | 09-26-2013 |
20130294911 | METHOD OF REDUCING A STRUCTURAL UNBALANCE IN A WIND TURBINE ROTOR AND DEVICE FOR PERFORMING THE METHOD - 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. | 11-07-2013 |
20130300116 | METHOD AND ARRANGEMENT FOR DAMPING A SHAFT OSCILLATION - A method for damping an oscillation of a rotational speed of a shaft of a wind turbine is described. A converter is connected between a generator and a wind turbine output terminal. The rotational speed of the shaft or the generator is measured. A DC-link voltage reference varying in dependence with the rotational speed is determined. A DC-link voltage of a DC-link of the converter according to the DC-link voltage reference is controlled. | 11-14-2013 |
20140232113 | METHOD FOR REDUCING VIBRATIONS OF A WIND TURBINE AND CONTROL SYSTEM FOR REDUCING VIBRATIONS - 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. | 08-21-2014 |
20140266861 | ARRANGEMENT TO MEASURE THE DEFLECTION OF A BLADE OF A WIND TURBINE - 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. | 09-18-2014 |
20150019276 | Method for Computer-Assisted Determination of the Usage of Electrical Energy Produced by a Power Generation Plant, Particularly a Renewable Power Generation Plant - 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. | 01-15-2015 |
20150025860 | METHOD AND DEVICE FOR ESTIMATING GRID PROPERTIES OF A POWER GRID - 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 V | 01-22-2015 |