Abstract: Control systems are described that mitigate the effects of icing events on wind turbines. Example methods include determining, with a control system, that an icing event has begun to affect the wind turbine; based on a determination that the icing event has begun to affect the wind turbine, changing a phase of the wind turbine with the control system to an operational-icing phase by modifying angles of attack of blades of the wind turbine via changing blade pitch angles, wherein the wind turbine continues to generate electrical power when the wind turbine is in the operational-icing phase; and based on a determination that electrical power generation of the wind turbine is below a threshold, changing the phase of the wind turbine with the control system to a stopped-icing phase, wherein rotation of the blades of the wind turbine is halted when the wind turbine is in the stopped-icing phase.

Abstract: The invention relates to a method for operating a wind turbine, to a wind turbine designed to carry out the method, and to a computer program product. The method for operating a wind turbine comprising a rotor with rotor blades that can be angularly adjusted via a turbine controller, in which a state variable that reflects the current thrust of the rotor is detected, has the following steps: a) ascertaining a short-term average value of the state variable; b) ascertaining the difference between the short-term average value of the state variable and the detected current state variable; c) ascertaining a first target blade angle correction value from the ascertained difference; and d) taking into consideration the target blade angle correction value while adjusting the blade angle by means of the turbine controller.

Abstract: For each of actuators, the partial load ratio is output. An output device for a drive device of a wind turbine includes an obtaining unit for obtaining information relating to a load applied to each of a plurality of actuators, where the actuators are included in the drive device of the wind turbine and configured to cooperate with each other, a processing unit for, based on the information obtained by the obtaining unit, calculating a partial load ratio, where the partial load ratio represents a ratio of a load on each of the actuators to a total load and the total load is a sum of the loads on the respective actuators, and an output unit for outputting the partial load ratio.

Abstract: Provided is a method for detecting a wind gust that affects a wind turbine, wherein the wind turbine includes two or more blades which are coupled to a connection means so that the blades are essentially arranged in a common plane. The method including: i) measuring an event that at least one blade is at least partially out of the plane to obtain a measurement signal, ii) providing the measurement signal as a measurement input signal to an evaluation algorithm, iii) elaborating a detection result from the measurement input signal using the evaluation algorithm, and iv) comparing the detection result with a predefined wind gust threshold value (h) to determine, if a wind gust is detected. Furthermore, a wind gust detection system, a wind turbine that includes the system, and a wind turbine operating method are provided.

Abstract: A fan control system for a variable pitch fan of a work vehicle includes a first sensor that measures a parameter of a cooling system and a blade pitch module that adjust a pitch of a plurality of blades of the variable pitch fan to generate airflow in a first direction. A reversing module selectively commands a fan reversal that includes instructing the blade pitch module to temporarily adjust the pitch of the plurality of blades to generate airflow in a second direction. A first timer module, in response to the reversing module commanding the fan reversal, resets and increments a first timer and compares the first timer to a first threshold. A first reversal prevention module, in response to the first timer being less than the first threshold, prevents the reversing module from commanding a fan reversal by indicating that a first type of fan reversal is not permitted.

Abstract: Systems and methods are described for governing the speed of a propeller on a propeller-based engine in an aircraft. The method comprises obtaining a synthesized or estimated blade angle for the propeller of the engine, determining one or more gain for a controller of the propeller based on the synthesized or estimated blade angle and one or more engine or aircraft parameter, determining a difference between a reference propeller speed and an actual propeller speed, applying the one or more gain to the difference via the controller in order to generate a command signal for controlling the propeller, and governing the propeller of the engine using the command signal.

Abstract: An inspection method according to the present disclosure includes a step of mounting an ultrasonic probe, a step of mounting a pulser receiver, a step of causing the ultrasonic probe to transmit ultrasonic waves, a step of causing the ultrasonic probe to receive a reflected wave of the ultrasonic waves reflected by the wind turbine blade, a step of causing the pulser receiver to acquire reflected-wave data, a step of causing the pulser receiver to wirelessly transmit the reflected-wave data, a step of causing at least one of antennas to receive the wirelessly transmitted reflected-wave data, and a step of causing an information processing device electrically connected to the at least two antennas to perform information processing on the reflected-wave data.

Abstract: A method for mitigating loads acting on a rotor blade of a wind turbine includes receiving a plurality of loading signals and determining at least one load acting on the rotor blade based on the loading signals. Further, the method includes determining a type of the load(s) acting on the rotor blade. Moreover, the method includes comparing the load(s) to a loading threshold, such as an extreme loading threshold. In addition, the method includes implementing a control scheme when the load(s) exceeds the loading threshold. More specifically, the control scheme includes providing a first pitching mode for reducing a first type of load, providing a different, second pitching mode for reducing a different, second type of load, and coordinating the first and second pitching modes based on the type of the at least one load to mitigate the loads acting on the rotor blade.

Abstract: A rotorcraft comprising a rotor blade designed to flap about a hinge point, a measurement system designed to measure blade flapping, and a processing system designed to alter blade flapping measurements. The processing system further comprises a correction process to alter a blade flapping measurement dependent on rotor RPM or rotor torque.

Abstract: A blade angle feedback assembly for an aircraft-bladed rotor, the rotor rotatable about a longitudinal axis and having an adjustable blade pitch angle, is provided. The assembly comprises a feedback device coupled to rotate with the rotor and to move along the longitudinal axis with adjustment of the blade pitch angle, the feedback device comprising a plurality of position markers circumferentially spaced around the feedback device, a plurality of sensors positioned adjacent the feedback device and each configured for producing a sensor signal in response to detecting passage of the position markers as the feedback device rotates about the longitudinal axis, the sensors circumferentially spaced around the feedback device and axially offset along the longitudinal axis, and a control unit communicatively coupled to the sensors and configured to generate a feedback signal indicative of the blade pitch angle in response to the sensor signals received from the sensors.

Abstract: Various embodiments of the present invention relate to a method and a device for controlling the operation of an external device on the basis of various states of an electronic device when the external device having a cooling function is connected in the electronic device. The electronic device according to various embodiments of the present invention comprises: an interface for connection with the external device; and a processer electrically connected to the interface. The processor can detect connection of the external device by means of the interface, determine the state of the electronic device on the basis of at least the detection of the connection with the external device, and transmit a control signal relating to fan operation control of the external device to the external device by means of the interface on the basis of at least the state of the electronic device. Various embodiments are possible.

Abstract: Provided is a system for determining a soiling state of a wind turbine rotor blade. The system includes a pressure sensor adapted to measure a plurality of pressure values corresponding to a plurality of different heights above a trailing edge region of the wind turbine rotor blade, and a processing unit in communication with the pressure sensor and adapted to determine the soiling state of the wind turbine rotor blade by estimating an air flow velocity distribution above the trailing edge region of the wind turbine rotor blade based on the plurality of pressure values. Furthermore, a corresponding method of determining a soiling state of a wind turbine rotor blade is described.

Abstract: A device for automatic control of an angular position of turbine blades of a propeller device, in which the turbine blades are rotatable about a rotational axis and are pivotally displaceable about their respective pivot axes. The device includes a set of control blades kinematically connected with the turbine blades, said control blades are pivotally displaceable about respective pivot axes once the propeller device is exposed to a flow of fluid. The device further includes a transmission unit configured for transmitting pivotal displacement of the control blades to the turbine blades such that the turbine blades could be pivoted by the control blades. Pivoting of the turbine blades takes place simultaneously with the pivoting of the control blades. The angular disposition of the turbine blades is automatically set and remains invariant irrespective of direction of the flow of fluid.

Abstract: A system and method for managing shadow flicker at a wind turbine site having at least one wind turbine includes determining, via a processor, a sun position of the wind turbine site. The method also includes receiving, via the processor, a spatial location of the at least one wind turbine with respect to at least one receptor. Further, the method includes determining, via the processor, whether shadow flicker is occurring at the at least one receptor based, at least in part, on the sun position and the spatial location of the at least one wind turbine. Moreover, the method includes implementing, via the processor, a corrective action for the at least one wind turbine when shadow flicker occurs at the at least one receptor to reduce the shadow flicker.

Abstract: A rotational positioning system in a wind turbine is provided that comprises a driven part, a plurality of positioning drives coupled to the driven part, a plurality of sensors each arranged to sense a load parameter indicative of the load of the respective positioning drive, and a load controller connected to the plurality of sensors. The load controller is arranged to determine a load of a respective positioning drive based on the sensed load parameter, to compare said load with an expected load value, and to output a signal indicative of a failure of the respective positioning drive in response to the load being smaller than the expected load value.

Abstract: Embodiments generally relate to assembly and methods for precisely rigging a linear variable differential transformer (LVDT). For example, the probe rod assembly of a dual tandem LVDT may comprise two moveable cores, a probe fitting, and a probe rod. Generally, the first moveable core may be configured to achieve electrical zero with its respective transformer. Without adjusting the position of the probe rod with respect to the one or more coils of wire, the second moveable core may be configured to achieve electrical zero with its respective transformer. This may ensure that both moveable cores simultaneously achieve electrical zero in the null position. Typically, the probe fitting may be configured to fit at a first end of the probe rod projecting outward from the outer housing. The disclosed assembly and methods may be used to precisely rig dual tandem LVDTs, single channel LVDTs, and dual parallel LVDTs.

Abstract: A system (10) having a control plate (15) for controlling the pitch of the blades (5) of a propeller, a power block (20), and a directional control valve (30) for feeding said power block (20) with fluid. The power block (20) is sealed and includes at least a body in which at least one piston (22) that is secured to a piston rod (25) projecting from said body (21) is movable in translation, a repeater rod (50) connecting said piston rod (25) to said control plate (15). The control valve (30) is sealed and comprises a stationary manifold (35) and a movable manifold (40) that is movable in rotation, said stationary manifold (35) being controlled by a control lever (31) connected by repeater means (32) to said repeater rod (50). A respective pipe (60) connects each chamber (23, 24) of said power block (20) to said movable manifold (40).

Abstract: A two-bladed partial-pitch wind turbine and a method of controlling such a wind turbine during high wind conditions are described. The turbine is operable to pitch the outer sections of the turbine rotor blades during extreme wind conditions (i.e., high wind loads) such that the outer blade sections are substantially orthogonal to the inner blade sections. This arrangement acts to reduce the extreme thrust loading experienced by the wind turbine structure during severe gusts (e.g., during hurricane or typhoon conditions), and accordingly reduces the risk of damage to the wind turbine in such conditions.

Abstract: The present invention relates to methods, apparatus and computer program products for coordinating the control of a floating wind turbine (101) between a wind turbine controller (111) and a platform controller (110). One or more wind turbine control systems and/or one or more platform control systems may be altered based on 102 said coordinated control of said floating wind turbine (101).

Abstract: The invention concerns a wind power installation comprising a pod, a rotor, a first and/or second microwave technology and/or radar technology measuring unit for emitting microwaves and/or radar waves and for detecting the reflections of the microwaves and/or radar waves to acquire wind data and/or meteorological data or information in respect of a wind field in front of and/or behind the wind power installation, and a control means of the wind power installation, which controls operation of the wind power installation in dependence on the data detected by the first and/or second measuring unit.

Abstract: The invention provides a wind turbine, a control system for a wind turbine and a method for controlling a wind turbine where asymmetry in load on the rotor is compensated by individual pitching by comparing a load distribution over the rotor plane with a threshold value. To avoid unnecessary compensation, the threshold value is adjusted based on a loading of the wind turbine or based on climate conditions under which the turbine operates.

Abstract: A method for noise-reduced operation a wind is provided. The method includes determining a wind speed during normal operation of the wind turbine and determining a weighted rotor speed setpoint for a rotor of the wind turbine so that a noise emission of the wind turbine for the wind speed is reduced compared to nominal noise emission of the wind turbine at the wind speed. Using the weighted rotor speed setpoint, a torque setpoint for a power conversion assembly connected to the rotor is determined. The torque setpoint is applied to the power conversion assembly to control the wind turbine.

Abstract: A wind turbine having a set of curved blades mounted on a central rotatable hub. Each of the blades has a defined pitch angle, to a rotational axis of the hub, along the blade from the hub to the tip. A curve is provided on the wind contact surface along each of the blades over the blade surface from the leading edge of the blade to the trailing edge of the blade by an amount between about 6 and about 24 degrees. The defined pitch angle from any point along the leading edge of the blade being defined by the arc-sine of a ratio of blade velocity to apparent wind velocity, with a variance of ±30 percent of the complementary angle to the arc-sine; and apparatus for varying the velocity of the blade to control power output so that it is within fifteen percent of maximum obtainable power of the blade most distant from the hub.

Abstract: A control system for calibrating a wind turbine sensor placed on a component of a wind turbine and related methods are disclosed. The wind turbine includes a rotor having at least one wind turbine blade. The method comprises pitching one or more of the at least one of the wind turbine blades according to a predetermined pitch movement which induces a vibratory motion in the at least one turbine blade. A wind turbine sensor measures a vibratory response signal at least partly caused by the vibratory motion. A characteristic sensor response value is determined from the vibratory response signal. The characteristic sensor response value may be compared to a predetermined sensor calibration parameter to determine whether a difference is greater than a predefined tolerance parameter. In this manner, the wind turbine sensor may be calibrated.

Abstract: A system for operating a rotating component. The system includes a rotating component, a motor driving the rotating component, a sensor detecting a stimulus related to the rotating component, and a controller. The controller receives an indication of the magnitude of the stimulus from the sensor and is configured to adjust a speed of the rotating component when the stimulus indicates the rotating component is operating at a resonant frequency.

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.

Abstract: An omni-directional air flow device, for example, a fan or a vent associated with a fan, comprises a swivel control point providing almost a spherical range of motion of the air flow device so that air may flow in any direction. The omni-directional air flow device may comprise a user input device for receiving a program for controlling movement of the air flow device through a pre-determined path within the spherical range of motion and for controlling air flow velocity as the air flow device follows the pre-determined path. Moreover, the device may further comprise a controller and memory for storing data representing the pre-determined path and varying air flow velocities along the path. When provided with temperature and humidity sensors coupled to the processor, the processor may calculate a comfort index and adjust the pre-determined path or air flow velocity accordingly.

Abstract: A blower having counter rotating fan blades for generating uniform air flow across a heat sink, which maximizes the cooling efficiency of the heat sink. The counter rotating fan blades may individually controlled to optimize performance of the blower. Only one set of fan blades may be used for low temperature conditions, thereby consuming less power and reducing acoustic noise, while both sets of fan blades may be used for high temperature conditions, thereby maximizing heat transfer. The blower may be configured to operate one or both sets of fan blades at a desired operating fan speed based on one or more pre-determined conditions. The pre-determined conditions include at least one of temperature, acoustic, and power levels and or measurements of one or more components of the computer system.

Abstract: A system and method for pressure based load measurement are provided. The system and method measure at least one pressure differential on an airfoil and determine at least one aerodynamic load associated with the at least one pressure differential. The determined at least one load is used to modify characteristics of the airfoil to increase efficiency and/or avoid damage. The determined at least one aerodynamic load may be further utilized to balance and/or optimize loads at the airfoil, estimate a load distribution along the airfoil used to derive other metrics about the airfoil, and/or used in a distributed control system to increase efficiency and/or reduce damage to, e.g., one or more wind turbines.

Abstract: A method for operating a wind power plant (WEA) before or during the performance of maintenance work on the wind power plant (WEA). At least one physical condition of the surroundings outside the wind power plant (WEA) induced by wind movement outside the wind power plant (WEA) is detected as an external physical condition. At least one physical condition of a component of the wind power plant (WEA) influenced by wind movement outside the wind power plant (WEA) is detected as an internal physical condition. The at least one external physical condition and/or at least one internal physical condition are evaluated. The at least one external physical condition is compared with a predetermined reference value for the external physical condition. The at least one internal physical condition is compared with a predetermined reference value for the internal physical condition. Depending on the comparison, at least one warning message is generated.

Abstract: A method and system for shutting down a wind turbine is presented. The method includes determining one or more pitch positions for one or more rotor blades of the wind turbine such that a sum of potential energy and kinetic energy in the wind turbine is minimized. The method further includes pitching the one or more rotor blades from an operating position to the determined pitch positions.

Abstract: An upwind wind turbine includes a tilting coupling mechanism configured to couple base end portions of blades to a hub such that the blades can tilt between a normal position and a retracted position in which the blades are tilted in a downwind direction relative to the normal position. The upwind wind turbine also includes a tilting drive operating in association with the tilting coupling mechanism to switch the positions of the blades and a rotation stop to stop the rotation of the rotor. When the blades are switched to the retracted position, the rotation stop is actuated to stop the rotor in a predetermined rotational position in which the blades can tilt without interference with the tower, and the tilting drive is actuated to tilt the blades to the retracted position after stop of the rotation of the rotor.

Abstract: Described embodiments include a wind turbine system. In this embodiment, the system includes a wind turbine including a rotor blade having a controllable feature and attached to a rotor hub drivingly coupled to an electric generator. The controllable feature is configured if activated to decrease a noise generated by the rotor blade and correspondingly to decrease electric power generated by the electric generator. The wind turbine system includes a sensor configured to detect a parameter indicative of present or possible future noise generation state of the rotor blade. The wind turbine system includes a noise manager circuit configured to select a noise mitigation measure responsive to the detected parameter and in compliance with a minimum electric power generation requirement assigned to the wind turbine. The wind turbine system includes a control circuit configured to activate the controllable feature in response to the selected noise mitigation measure.

Abstract: The invention comprises a turbulence sensor and sensor system for determining the condition of a wind turbine blade. A turbulence sensor comprises a sensor membrane provided in the surface of a wind turbine blade. A light source and light detector provided in a sensor cavity in the blade illuminate the sensor membrane and detect the light reflected back. The reflected light is mixed with non-reflected light to give an interference pattern indicative of the quality of the airflow, whether it is laminar or turbulent. The turbulence sensor can be used in a sensor system for detecting the accumulation of unwanted matter, such as dirt or ice, on the blade.

Abstract: System for stabilizing an offshore horizontal axis wind turbine having a tower, the system comprising sensors for generating signals representing detected movements of the tower, and gyroscopes. Each gyroscope has a spinning axis, an input axis and an output axis, and a flywheel rotatable about the spinning axis. The system further comprises an actuator for each gyroscope, said actuator being arranged with its related gyroscope in such a way that this actuator can apply a torque about the input axis of the gyroscope. The system also comprises a control unit for receiving the signals representing detected movements of the tower, and for providing the actuator with suitable control signals for said actuator to apply a torque about the related gyroscope input axis, said torque about the input axis producing a torque about the output axis of the same gyroscope that at least partly dampens the detected movements of the tower.

Abstract: The present invention relates to a method of controlling an idling wind turbine in which wind condition data and wind turbine position data are collected by a sensor system, a control system computes an optimal pitch angle for a rotor blade of the wind turbine, and a pitching system continuously turns the rotor blades in the same direction in multiples of 360 degrees. The present invention further relates to a wind turbine with a sensor system including a wind sensor that measures wind condition data in the vicinity of the wind turbine, and a control system including a computer that executes a control algorithm and processes sensor input from the sensor system to compute an optimal pitch angle value for a rotor blade on the hub. This allows pitching the rotor blade into angle in which the mechanical loads of that rotor blade are reduced to a minimum when idling.

Abstract: Blades of a wind turbine attached to a rotor hub for rotation in a rotor plane may be adjusted by a control system for individually pitching the blades relative to the hub. The rotor planes divided into a plurality of predefined section, wherein each section has an associated pitch reference value. A light detection and ranging device may be used to determine expected properties of wind in each respective section of the rotor plane so that the pitch reference value may be adjusted accordingly.

Abstract: A system for arranging and operating an array of wind machines to protect crops from damaging weather conditions, such as freezing frost, rain and heat. The method includes a wind machine positioned to force air across the crop. The wind machine is preferably a propeller/tower configuration. The operational method of the wind machine array includes the steps of sensing ambient meteorological and the hardiness of the crop to withstand a particular adverse weather condition and operating the wind machines in response to these factors. Multiples of wind machines are employed in the preferred embodiment of the method, the siting of the wind machines preferably based upon topographic and historical meteorological conditions. The operation of the wind machines can be automatically and remotely operated with the aid of satellite communications including internet links.

Abstract: There is provided a yaw rotation control method for a wind turbine generator that does not require a yaw motor and is advantageous for a reduction in cost and a reduction in size and weight of a nacelle. A control unit performs, according to a deviation between wind direction information (?w) obtained from a wind direction detecting unit and a present state yaw angle (?z) obtained from a yaw rotating position detecting unit, yaw rotation control for outputting pitch angle command values (?1, ?2, and ?3) of yaw rotation to a pitch driving unit and directing front surfaces of rotation surfaces of wind turbine blades at the time of start. This yaw rotation control includes a step of controlling pitch angels of the wind turbine blades at a predetermined azimuth angle.

Abstract: A wind turbine generator is provided in which the efficiency of heating the interior of a nacelle can be improved at a low outside air temperature in a cold region. The wind turbine generator includes a nacelle that accommodates a driving and generating mechanism connected to a rotor head fitted with turbine blades, wherein the nacelle is equipped with a lubricant-oil cooling fan and a generator cooling fan that ventilate the interior of the nacelle to prevent an increase in the temperature of the interior and a heating device that raises the temperature of the interior of the nacelle at a low outside air temperature, wherein the cooling fans can be operated with the rotating directions and the rotational speeds thereof being controlled, and during the operation of the heating device, the rotating directions and the rotational speeds of the cooling fans are controlled so as to make the wind velocity at the ventilation ports thereof about zero.

Abstract: A method for shutdown of a wind turbine having one or more wind turbine blades includes detecting an operational condition of the wind turbine that calls for an expedited or emergency shutdown of the wind turbine by a manner other than normal pitch control shutdown. Upon detection of the operational condition, one or more air brake flaps configured on each of the turbine blades is deployed by removing power to a fail-safe actuator operatively coupled to each of the air brake flaps. The fail-safe actuator is configured to hold the respective air brake flap at a retracted position relative to a suction side of the turbine blade in a powered state of the fail-safe actuator and to release the air brake flap for automatic deployment to an open position upon loss of power to the fail-safe actuator.

Abstract: The method consists in determining at least one of wind turbine operating conditions or parameters related to pitch activity 116-119; determining if lubrication is needed depending on at least the operating conditions or the pitch activity parameters 116-119; and causing lubrication of the pitch blade bearing if lubrication is determined to be needed. Lubrication may consist in injecting grease during a period of time and causing the blades of the wind turbine to be rotated if necessary during grease injection. The device includes means for determining wind turbine operating conditions, means for determining parameters related to pitch activity, a wind turbine main control 100 for determining if lubrication is needed depending on operating conditions and pitch activity parameters 116-119, and means for causing lubrication of the pitch blade bearing if lubrication is needed.

Abstract: A method of controlling a wind turbine is provided. The method includes the steps of obtaining a number of operating values relevant to a wind turbine, calculating a thrust setpoint on the basis of the operating values, and controlling a wind turbine according to a thrust setpoint. A wind park controller, a wind turbine controller, and a wind park are also provided.

Abstract: In this presentation, we study various aspects of the wind turbines or wind mills. We optimize the performances of both a single wind turbine and a wind farm, collectively. We study the nozzles on the blades and all the variations and accessories for the operation of a nozzle. We also explore flow patterns around the blades, the mechanisms to get air or other gasses to the blades, the couplers for the electrical connections and the gas connections, and the gaps, holes, channels, conduits, or openings on the body or structure of a tower. We also present various mathematical models and formulations for optimizations.

Abstract: A hydraulic cylinder is coupled to blades of a wind turbine generator and actuated to change a pitch angle of the blade. A variable displacement hydraulic pump supplies hydraulic oil to the hydraulic cylinder, and a discharge pressure of the pump does not follow a load pressure. When the discharge pressure of the hydraulic pump becomes a set pressure, a pressure control valve is opened to change a discharge amount of the hydraulic pump, and to make the discharge pressure of the hydraulic pump to be a pressure smaller than a cut off pressure. Further, a setting control unit sets the set pressure based on the hydraulic pressure that the hydraulic cylinder requires such that the set pressure becomes a minimum pressure required to change the pitch angle to a predetermined angle by the hydraulic cylinder.

Abstract: A system and method are provided to increase efficiency of turbines in wind farms. A sensor is configured to detect direction and speed of an inflow of wind. A controller is configured to generate a control signal based the detected direction and speed of the inflow of wind. A pitch adjustment device configured to adjust pitch of a blade of the turbine based on the control signal.

Abstract: A method and an apparatus for measuring an air flow at an airfoil surface are provided, wherein at least one pressure sensor adapted to detect an air flow associated with a rotor blade surface and a pressure transducer which converts the detected air flow into an electrical signal indicating the air flow are provided. The pressure sensor is arranged within the boundary layer of the air flow at the airfoil surface such that the boundary layer profile may be determined from the electrical signal. The air flow sensor is adapted for rotor blades of a wind turbine to assist in adjusting a pitch angle of the rotor blades.

Abstract: A method and an apparatus for adjusting a yaw angle of a wind turbine comprising a rotor having a plurality of rotor blades and a hub are provided. The method is adapted for adjusting the yaw angle from an actual yaw angle to a desired yaw angle and comprises the steps of measuring a wind direction at the location of the wind turbine, measuring the yaw angle of the wind turbine and/or determining a wind direction relative to the nacelle orientation, calculating a pitch angle of at least one rotor blade as a function of the measured wind direction and the measured yaw angle and/or the wind direction relative to the nacelle orientation, and adjusting the pitch angle of the rotor blades according to the calculated pitch angle such that a yaw momentum is generated for changing the yaw angle from the actual yaw angle to the desired yaw angle.

Abstract: A wind power plant comprising a plurality of wind turbines, the power plant further comprising: a power plant controller connected to at least a first and a second of the plurality of wind turbines; the power plant controller comprising means for detecting a shutdown of the first wind turbine in response to current wind conditions; the power plant controller further comprising means to control the second wind turbine such that an operating parameter of the second wind turbine is modified in response to a detection of a shutdown of the first wind turbine in response to current wind conditions.

Abstract: It is an object to make it possible to completely or partially eliminate a yaw driving device and to reduce power consumption in a nacelle. A moment around a wind-turbine tower axis is calculated; an angle command value around the wind-turbine tower axis is calculated by adding a yaw-control command value to a reference command value for canceling out the moment; and a pitch angle command value of each wind turbine blade is set on the basis of the angle command value around the wind-turbine tower axis.