Abstract: A system and methods for reducing vibration in a rotatable member are provided. The system includes a blade tracking sensor, a rotatable member comprising an adjustable aspect, and a control computer. The control computer is configured to determine an axial position of each blade, determine a first blade that is displaced by a greatest distance along the axis in a first direction, modify an aspect of the first blade to facilitate reducing a vibration in the rotary blade system, determine if the vibration level in the rotary blade system is reduced, and select another rotatable member to modify such that a vibration in the rotary blade system is facilitated being further reduced.

Abstract: Load control systems and methods for shafts are provided. The load control system includes a sensor assembly. The sensor assembly includes a plurality of ultrasonic probes mounted to the shaft, each of the plurality of ultrasonic sensors configured to produce an ultrasonic wave on the shaft. The sensor assembly further includes a plurality of receivers mounted to the shaft, each of the plurality of receivers configured to sense the ultrasonic wave produced by one of the plurality of ultrasonic probes. The load control system further includes a controller communicatively coupled to the sensor assembly and configured to measure a travel time of the ultrasonic wave produced by each of the plurality of ultrasonic probes.

Abstract: The main subject matter of the invention is a device (1) for setting a turbomachine propeller blade (2), characterised in that it comprises a first disc (3) and a second disc (4) respectively provided with first (5) and second (6) coupling means, the first (3) and second (4) discs being coaxial, means of tilting (9, 10, 11, 12) at least one of the first (3) and second (4) discs with respect to the other, the device (1) being configured so that, during a tilting of at least one of the first (3) and second (4) discs with respect to the other, the coupling distance (D) of said at least one blade (2) on the first (3) and second (4) discs remains constant, bringing about the rotation of said at least one blade (2).

Abstract: A wind turbine includes multiple blades, multiple Micro Inertial Measurement Units (MIMUs) for sensing parameter signals of the blades, and a control system. The control system includes a blade bending moment calculation unit, a blade bending moment error signal calculation unit, and a pitch angle compensation command calculation unit. The blade bending moment calculation unit is used for calculating blade bending moment values of the blades based at least on the sensed parameters. The blade bending moment error signal calculation unit is used for calculating blade bending moment error signals of the blades based on the calculated blade bending moment values of the blades and multiple blade bending moment commands. The pitch angle compensation command calculation unit is used for calculating pitch angle compensation commands of the blades based on the calculated blade bending moment error signals to adjust pitch angles of the blades respectively.

Abstract: A method of operating at least one wind turbine is described, comprising: determining a plurality of stress events of at least one component of the at least one wind turbine; determining at least one accumulated stress from at least two of the plurality of stress events; determining at least one residual lifetime based at least partially on the at least one accumulated stress.

Abstract: A method of and apparatus for operating a propeller, the propeller moving through a fluid, the method including: measuring a value of a property of the fluid (e.g. a parameter related to the density of the fluid); measuring a value of a parameter, the parameter related to one or more forces applied to the propeller (e.g. a torque applied to the propeller) or derived at least in part from the action of the propeller (e.g. a thrust produced by the action of the propeller, a drag produced by the action of the propeller, or a velocity produced by the action of the propeller); and controlling the propeller depending on a function of the measured value of the property of the fluid and the measured value of parameter. The propeller may be a propeller on an aircraft.

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: A stall sensor for a wind turbine is provided. A wind turbine including such a stall sensor and a method of operating such a wind turbine are also provided. The stall sensor includes detector means adapted to measure vibration of a rotor blade of the wind turbine and to output a vibration signal representative of the vibration of the rotor blade, conversion means connected to the detector means and adapted to determine a noise figure representative of a spectral signal content within a frequency band of the vibration signal received from the detector means and arbiter means connected to the conversion means and adapted to signal a presence or an absence of stall based on the noise figure received from the conversion means.

Abstract: The invention provides a wind turbine comprising a rotatable drive train including at least one bearing (3) and a pump (4) for supply of a lubricant to the bearing (3). The wind turbine further comprises a controller for performing closed loop control of the pump (4) to provide an amount of lubricant which varies depending on an actual state of operation.

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: A horizontal axis wind turbine with a ball-and-socket hub is disclosed. The hub enables horizontal axis turbines with two or more blades to teeter in response to wind shear gradients. The new hub design for a turbine equipped with three blades has been modeled using modified FAST code and has shown significant advantages over present three-bladed turbines with fixed hubs in reducing loads on the blades, tower, main shaft and bearings. The new hub design for a turbine equipped with three blades has also shown significant advantages over present two-bladed teetering turbines in reducing loads on the blades and tower. A likely additional advantage of a ball-and-socket hub equipped with three blades over a teetering hub with two blades is that wider teetering ranges are possible due to the significantly reduced likelihood for resonant teetering.

Abstract: A rotor blade is used in combination with a submersible electrical generator for generating electricity to be put into the grid, where the pitch of the rotor blade is controlled by a microprocessor. The microprocessor controls a radio frequency transmitter which emits signals to a receiver which controls a hydraulic value. The hydraulic valve controls a push-pull arrangement which through a right angle gear and pitch adjustment axial adjust the rotor pitch according to pre-programmed conditions stored in the microprocessor.

Abstract: The present invention relates to a control and regulation method for a rotorcraft having at least one variable-pitch propulsive propeller driven by at least one power source, said method consisting in generating at least one mean pitch setpoint ?tcl* for the propeller(s) as a function of a thrust variation control order Tcl, wherein the method consists in defining a plurality of operating modes, including: a direct mode in which the value of the mean pitch value is a direct result of the control order Tcl; a forced mode in which the mean pitch is automatically forced to a calculated pitch value; a regulated mode in which the power of the propulsive propeller(s) is regulated as a function of a power setpoint from a pilot and of servo-controlling the mean pitch of the propeller(s); and a protected mode.

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 method and a system for operating a wind turbine (10) during a fault. The system includes a pitch motor for rotating each rotor blade (18), second pitch sensors (72) for determining when the rotor blade (18) is rotated to a set point, and a backup pitch controller (80). After a fault is detected, the method determines whether the wind speed in the vicinity of the wind turbine (10) is less than or greater than or equal to a maximum rated velocity of the wind turbine (10). The backup pitch controller (80) then rotates the rotor blades (18) to a specific set point based on the determination.

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: A method of calibrating one or more load sensors of a blade of a wind turbine, said wind turbine comprising a main generator, a power electronic converter connected with the main generator, and a rotor operationally connected with the main generator and carrying the blade. The method comprises acting on the power electronic converter to operate the main generator as motor to set the blade in at least one predetermined condition. The method further comprises measuring loads in the predetermined condition using the load sensors of the blade and calibrating the blade load sensors taking into account the measured loads.

Abstract: A vibration suppressor system includes an annular electric motor system which independently controls rotation of at least two masses about the axis of rotation to reduce in-plane vibration of the rotating system. A method of reducing vibrations in a rotary-wing aircraft includes independently controlling a relative angular position of a multiple of independently rotatable masses to reduce vibrations of a main rotor system.

Abstract: A compressor airfoil tip clearance optimization system for reducing a gap between a tip of a compressor airfoil and a radially adjacent component of a turbine engine is disclosed. The turbine engine may include ID and OD flowpath boundaries configured to minimize compressor airfoil tip clearances during turbine engine operation in cooperation with one or more clearance reduction systems that are configured to move the rotor assembly axially to reduce tip clearance. The configurations of the ID and OD flowpath boundaries enhance the effectiveness of the axial movement of the rotor assembly, which includes movement of the ID flowpath boundary. During operation of the turbine engine, the rotor assembly may be moved axially to increase the efficiency of the turbine engine.

Abstract: A wind turbine control system is provided. The control system has a wind turbine controller arranged locally at the wind turbine and adapted to adjust operation parameters of the wind turbine, and a central control unit arranged remotely from the wind turbine and adapted to communicate with the controller. The central control unit has a module for virtualizing a first computing device and a second computing device. The first computing device monitors information provided by sensors of the wind turbine and received by the central control unit. The central control unit generates a control signal based on the received information and provides a control signal to the second computing device. The second computing device generates an adjusting signal based on the control signal to the wind turbine controller for controlling the operation of the wind turbine by adjusting operation parameters of the wind turbine.

Abstract: A method for controlling a pitch angle of blades of a wind turbine rotor during an emergency stop process of the rotor from an operating state, includes the steps of: (i) continuously determining a measure of an angular acceleration of the rotor, (ii) initiating pitching of the rotor blades and continuing pitching until a time (t2) where the determined angular acceleration of the rotor is substantially zero, and (iii) resuming pitching of the rotor blades at the end of a predetermined time period (t3-t2) after the time (t2) where the determined angular acceleration of the rotor was substantially zero. A wind turbine including an emergency stop control system having a mechanism for controlling an emergency stop process of the wind turbine rotor according to such a method is also contemplated.

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 for detecting loads in a wind turbine is disclosed. In one aspect, the system may generally include a shaft and first and second pillow blocks receiving portions of the shaft. The second pillow block may be spaced axially apart from the first pillow block. Additionally, the system may include at least one sensor configured to indirectly detect loads transmitted through at least one of the first pillow block and the second pillow block.

Abstract: A pressure relief device includes a main body and at least two air control units. The main body has at least one passage therein and two outlets formed at upper and lower ends of the passage. A lid is pivotally connected to each of the outlets. The two air control units are each disposed in the passage close to the lid. An air control device drives the air control units to open/close the lid which is adapted to open/close the passage.

Abstract: Embodiments of the invention provide methods, systems, and apparatus for determining a property of wind approaching a wind turbine. A light detection and ranging equipment may be used to determine a property of the wind at a plurality of locations ahead of a turbine. A wind flow model may be used to determine the property of wind expected at the rotor of the wind turbine based on the readings of the light detection and ranging device.

Abstract: This invention relates to a method and apparatus for controlling power distribution in an electrical aircraft propulsive system having at least one electrical propulsion unit which includes a plurality of rotatable blades, each blade having an adjustable pitch; a pitch adjusting mechanism for adjusting the pitch of the blades; at least one electrical machine electrically connected to the electrical propulsion unit so as to provide electrical power when in use; and, a control system, the method comprising the steps of: determining the required propulsion; determining whether the propulsive units are delivering the required propulsion; and, adjusting the pitch angle of the blades of at least one propulsive unit so as to increase or decrease the propulsion provided by that propulsive unit.

Abstract: A variable vane control system for use with a gas turbine engine includes an actuator, a mechanical linkage assembly, and a vane position sensor. The gas turbine engine has a plurality of variable vanes each having an airfoil disposed in a gas flow path of the gas turbine engine. The plurality of variable vanes includes a first variable vane. The mechanical linkage assembly operably connects the actuator to at least the first variable vane. The vane position sensor is connected to one of the first variable vane or a portion of the mechanical linkage assembly proximate the first variable vane for sensing angular position of the first variable vane.

Abstract: A reconfigurable rotor blade system includes an internal mass that is configured to translate in order to produce a spanwise torsional twist of the rotor blade. An actuator is configured to selectively translate the mass so as to relocate a center of mass of the rotor blade. The torsional twist is selectively produced during operation of the rotorcraft.

Abstract: A turbine includes a rotor, a fluid bearing for rotatably supporting the rotor, an air supply conduit system for supplying air towards the fluid bearing, a discharge conduit system for discharging a portion of the supplied air and a control system arranged to change an amount of air discharging through the discharge conduit system based on a running condition of the turbine.

Abstract: A turbomachine has a housing, a rotor shaft extending along and rotatable about an axis in the housing, and a pair of axially spaced axial-thrust bearings in the housing carrying the shaft and normally only permitting a predetermined small axial displacement of the shaft in the housing. An impeller is rotationally fixed on the shaft. An axially fixed transmission gear is rotationally coupled to the shaft and has an axially directed gear face. A collar fixed axially on the shaft has an axially directed collar face confronting the gear face and normally spaced from the gear face by a clearance equal to more than the predetermined axial displacement. Thus on failure of one of the bearings and axial overtravel of the shaft the gear face and collar face engage each other and limit axial movement of the shaft.

Abstract: A method for lubricating a bearing of a variable-pitch wind turbine is disclosed. The electrical capacitance and/or resistance of the bearing is measured and the state of lubrication of the bearing by is determined from the measurement. The bearing is lubricated when state of lubrication indicates that the bearing is insufficiently lubricated.

Abstract: To provide a horizontal axis wind turbine capable of reducing flutter, and by extension, reducing the load on the wind turbine, without controlling the yaw, regardless of the direction of the wind relative to the nacelle. When the wind speed is above a specific value, the yaw angle of the nacelle is held constant, the blade pitch angle is controlled according to the yaw angle Y of the wind direction relative to the nacelle, and the rotor is allowed to rotate freely. Even when the yaw angle of the nacelle is held constant, allowing the rotor to rotate freely makes it possible to reduce the load by avoiding flutter.

Abstract: A method of validating a wind turbine including a rotor includes intentionally inducing a loading imbalance to the rotor. The method also includes measuring the loading imbalance induced to the rotor, transmitting a signal representative of the measured loading imbalance to a calibration module, and at least one of detecting an error and calibrating at least one component of the wind turbine based on the signal.

Abstract: The invention relates to a device for monitoring a wind energy installation (1) comprising a tower (2) and a rotor provided with rotor blades (5) and arranged on the tower, in terms of a possible collision of a rotor blade (5) with the tower (2). Said device comprises at least one distance sensor (7a, 7b) which is arranged on the wind energy installation (1) and used for the non-contact measurement of the distance between the rotor blades (5) and a pre-determined point on the wind energy installation (1). The device also comprises an electronic evaluation system in which the distance data measured by the at least one distance sensor (7a, 7b) is evaluated, said system emitting a collision warning in the event of a critical distance not being reached.

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.

Abstract: A method is provided for operating a wind turbine having an elongated stand apparatus, a generator rotatably mounted on the stand apparatus, and a rotor coupled to the generator via a rotor hub and the wind turbine also having an elongated rotor blade. A position of a radar system is determined with respect to the wind turbine and at least one area is determined for the rotational axis of the rotor as a function of the determined position which is not intended to be permanently assumed for alignment of the rotational axis of the rotor about the longitudinal axis of the stand apparatus. The wind turbine is operated with the at least one determined area not being permanently assumed for the alignment of the rotational axis of the rotor about the longitudinal axis of the stand apparatus.

Abstract: A braking device and method are provided for a wind turbine. The wind turbine includes a rotor, a generator and a drive train having one or more components. The drive train is connected to the generator for obtaining electrical energy from rotation of the drive train. The wind turbine further includes a braking device for braking at least one drive train component of the drive train. The braking device includes a wedge brake.

Abstract: A control system for rotor blade control is discussed. The control system comprises a number of turbulence sensors provided across the surface of a wind turbine blade. The control system monitors the turbulence sensors and when turbulent air flow is detected controls an aerodynamic parameter of the of the blades. In one embodiment, the parameter is the pitch of the rotor blades. This means that stall-like blade conditions can be avoided, and power generation from the wind turbine can be optimised. The control system may also use measurements of output power as a control system to which the turbulence based measurements add extra responsivity and finer control.

Abstract: A wind turbine includes a rotor having a hub and at least one rotor blade, wherein the operating height of the hub is adjustable. Further, a method for operating a wind turbine is provided, which includes varying the height of the wind turbine.

Abstract: An active flow control system for use with a wind turbine is provided. The wind turbine includes at least one blade. The active flow control system includes an air distribution system at least partially defined within said at least one blade. The air distribution system includes at least one aperture defined through the at least one blade. An aperture control system is in operational control communication with the air distribution system. The aperture control system includes an actuator at least partially positioned within the at least one blade and configured to control a flow of air discharged through the at least one aperture.

Abstract: A system for detecting loads in a wind turbine is disclosed. In one aspect, the system may generally include a shaft and first and second pillow blocks receiving portions of the shaft. The second pillow block may be spaced axially apart from the first pillow block. Additionally, the system may include at least one sensor configured to indirectly detect loads transmitted through at least one of the first pillow block and the second pillow block.

Abstract: A pilot circuitry is disclosed for controlling the activation of an emergency feathering system of a wind turbine by means of a pilot pressure, wherein the pilot circuitry comprises at least two parallel control circuits for providing a pilot pressure. Additionally, a selector may provided for selectively preventing a control circuit from providing the pilot pressure to the emergency feathering system in case of malfunction of the control circuit.

Abstract: A wind energy plant with a nacelle, a rotor, which features at least one rotor blade adjustable in its blade pitch angle, a central control device for controlling the wind energy plant and a control unit disposed in the rotor for controlling the blade pitch angle of the at least one rotor blade, wherein the central control device and the control unit in the rotor can exchange data with each other via a data link, which comprises at least one first sending and receiving device at the nacelle side and at least one second sending and receiving device at the rotor side, wherein a wireless network connection with a safety-oriented communication protocol is provided between the at least one first sending and receiving device and the at least one second sending and receiving device, and that one monitoring- and communication device at a time is associated to the first and/or the second sending and receiving device, which can monitor the function of the sending and receiving device and initiate a predetermined action

Abstract: A method in connection with a wind turbine installation for damping tower vibrations, in particular a floating wind turbine installation comprising a floating cell, a tower arranged over the floating cell, a generator mounted on the tower that is rotatable in relation to the wind direction and fitted with a wind turbine, and an anchor line arrangement connected to anchors or foundations on the sea bed. The tower's eigenvibrations, ?eig, are damped by, in addition to control with the controller in the constant power or RPM range of the wind turbine, an increment, ??, being added to the blade angle of the turbine blades on the basis of the tower velocities, ?Z, so that the eigenvibrations are counteracted.

Abstract: Embodiments of the invention generally relate to controlling a wind turbine comprising blades attached to a rotor hub for rotation in a rotor plane and 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: The invention relates to a wind turbine comprising a substantially tubular tower structure and one or more vibration damping systems. At least one of the one or more vibration damping systems include a plurality of bracing elements and a damping element. One of the bracing elements is connected to the tower structure. The bracing elements and damping element are linked in such a way that a local displacement of the tower structure causes an increased displacement of the damper along its longitudinal axis. The invention further provides a method of damping vibrations in a wind turbine tower using one or more toggle-brace vibration damping systems and a using a toggle-brace vibration damping system for damping vibrations in a wind turbine.

Abstract: A rotor blade is used in combination with a submersible electrical generator for generating electricity to be put into the grid, where the pitch of the rotor blade is controlled by a microprocessor. The microprocessor controls a radio frequency transmitter which emits signals to a receiver which controls a hydraulic value. The hydraulic valve controls a push-pull arrangement which through a right angle gear and pitch adjustment axial adjust the rotor pitch according to pre-programmed conditions stored in the microprocessor.

Abstract: In a method for monitoring the load on rotor blades of wind energy installations by measuring acceleration on at least one rotor blade of a wind energy installation and determining load on the rotor blade from the picked-up acceleration signals, dynamic, even uncritical load states can be detected, in differentiated fashion, and combined in a suitable form for evaluation in order to influence, if possible prior to the onset of damage to the rotor blade, the mode of operation of the wind energy installation, in particular the design of the pitch control or angle setting of stall-regulated rotor blades, on the basis both of all of the rotor blades together and of a single rotor blade. Frequency of occurrence of the load values over a certain period of time is determined from amplitudes of the acceleration signal or amplitudes of selected natural oscillations of the frequency spectra are obtained by Fourier transformation.

Abstract: Wind turbine, yaw system controller and yaw system for a wind turbine and method of reducing the loads on such a yaw system. A method for reducing the loads acting on a wind turbine yaw system (19) due to yawing moments which are induced to the yaw system (19) 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 (19) 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.