Abstract: A method for dampening oscillations in a wind turbine, the wind turbine having a tower (1), a rotor (3) rotating about an X axis, and a plurality of blades (4) with adjustable pitch, said method comprising monitoring the fore-aft oscillation of the tower in the direction of the X axis, at the 2nd or a higher bending mode frequency; determining a compensating torque to be applied by the rotor to the tower about a Y axis, which is horizontal and at right angles to the X axis, for dampening said oscillation at the 2nd or higher bending mode frequency; determining for each rotor blade an adjustment of the pitch angle suitable to generate said compensating torque about the Y axis; and adjusting the pitch angle ?1, ?2, ?3 of at least one of the individual blades to generate at least part of said compensating torque.

Abstract: Method for operating an offshore wind farm with at least one wind turbine system and a navigation device, which is operated in a normal mode, wherein a hazard signal is received by a receiving device, the received hazard signal is supplied to a control device that switches the navigation device from the normal mode to a an emergency lighting mode.

Abstract: The invention relates to a device for rotating a rotor of a wind turbine. Here, the wind turbine has the rotor, a tower, a nacelle with a machine frame, and a hub on which at least one rotor blade can be mounted. The rotor is arranged so as to be rotatable relative to the nacelle about an axis of rotation. The wind turbine furthermore has a locking device for blocking a rotational movement of the rotor about the axis of rotation. The device has at least one first displacement unit which is fastened to the machine frame. The first displacement unit also has a fastening device by means of which the first displacement unit can be detachably fastened to the rotor. Finally, the fastening device is actuable, in particular electrically and/or hydraulically actuable. The invention furthermore relates to a system for rotating one rotor of the wind turbine. The invention finally relates to a method for rotating the rotor of the wind turbine by means of the device or by means of the system.

Abstract: A wind power plant having a sliding bearing with a first and second bearing component which are arranged to rotate relative to one another about a common rotational axis is provided. The sliding bearing has at least one sliding lining arranged between the first and second bearing component and has a contact face with a lubricant. The contact face has a sliding lining duct opening to a sliding lining duct, wherein the sliding lining duct crosses the sliding lining and feeds lubricant into a region between the first and second bearing component. The sliding lining has a groove on the contact face, surrounding the sliding lining duct opening. An operation of the wind power plant to generate electric current is also provided. The sliding bearing operates hydrostatically during a startup phase of the rotational movement and/or operates hydrodynamically during a phase of the rotational movement with a constant rotational speed.

Abstract: The invention relates to a method of controlling a wind turbine comprising one or more blades attached to a rotor hub, the one or more blades being arranged to pitch relative to the hub, the method comprising the steps of obtaining a blade load signal comprising data on an absolute load on the one or more blades; processing the blade load data to detect a high thrust wind event, and generating a control signal comprising a pitch contribution for affecting the blades to pitch out of the wind in response to the detected wind event. The invention also relates to a wind turbine, a control system for a wind turbine and a computer program product being adapted to enable a computer system to perform the method of the invention.

Abstract: Methods for producing ultrasonic sound emissions from wind turbines, active systems for emitting ultrasonic sounds from wind turbines, and wind turbines are provided. In one embodiment, a method includes operating the wind turbine with an ultrasonic sound emitting device mounted on or within a component of the wind turbine, and receiving in a controller at least one indicator. The method further includes determining if an operating condition exists based on the at least one indicator, and supplying a fluid flow through an outlet of the ultrasonic sound emitting device such that an ultrasonic sound emission is produced by the ultrasonic sound emitting device if the operating condition exists.

Abstract: Method for controlling a wind turbine, comprising the steps of determining a boundary layer profile of the wind coming towards the wind turbine, determining the wind velocity at a predetermined height based on the boundary layer profile, and operating the wind turbine to maintain the emitted noise below a predetermined noise level when the wind velocity at the predetermined height is below a predetermined value.

Abstract: Methods and apparatus for optically detecting an angle of attack for an airfoil using light detection and ranging (LIDAR). To determine the angle of attack, one or more light beam pulses may be emitted from the leading edge of the airfoil into an (apparently) flowing fluid at various emission angles. The emitted pulses may be backscattered by particles in the fluid, and the backscattered light may be received by a detector at the airfoil. By range gating the returning pulses of backscattered light, a fluid velocity may be determined for each of the emission angles. The angle of attack is identified as the emission angle corresponding to the maximum velocity. A parameter (e.g., pitch or speed) of the airfoil may be controlled based on the angle of attack. In this manner, the airfoil may be manipulated or the shape of the airfoil may be adjusted for increased performance or efficiency.

Abstract: Systems and methods for blade health monitoring are provided. According to one embodiment of the disclosure, a system may include a feature extraction module and an anomaly detection module in communication with the extraction module. The feature extraction module may be configured to continuously receive blade passing signal data associated with clearance of a blade and pre-process the blade passing signal data. Blade clearance feature data may be extracted from the blade passing signal data prior to transmission to the anomaly detection module. The anomaly detection module may be configured to normalize the blade clearance feature data received from the extraction module, analyze the blade clearance feature data to detect a shift in the clearance of the blade, and determine an abnormality of the blade based on the shift exceeding a predetermined shift threshold.

Abstract: There is provided a system for harvesting drag force acting on a moving vehicle, the system comprising a fan comprising blades and a fan rotating shaft, the fan being configured to be mounted on the moving vehicle for receiving air flow resulting from the drag force acting on the moving vehicle such that the air flow act on the blades during movement of the vehicle impelling rotation of the blades, and wherein the fan rotating shaft is adapted to be connected to and in movement cooperation with the blades for rotating by the effect of the rotation of the blades for converting the air flow into kinetic energy. There is further provided a method of harvesting drag force acting on a moving vehicle, the system comprising converting air flow resulting from the drag force acting on a moving vehicle into kinetic energy, and converting the kinetic energy into at least one of mechanical energy and electrical energy for operating mechanical and electrical components of the vehicle respectively.

Abstract: The method for de-icing composite material structures, particularly blades of a wind turbine made from composite materials, includes the following steps: disposing at least one layer of a formulation of conductive polymer on at least one portion of the surface of the structure, providing an appropriate electrical power supply for the structure, and connecting the layer of a formulation of conductive polymer to the electrical power supply in such a way as to cause the conductive layer of conductive polymer to heat up, controlling the electrical power supply depending on climatic conditions. The required composition and suitable device are also described. A specific application is the blades of wind turbines.

Abstract: A method of assisting in rotor speed control in a rotorcraft can include measuring a rotor speed with a sensor; detecting a droop in the rotor speed beyond a lower droop limit; and commanding a decrease in collective in response to the rotor speed drooping beyond the lower droop limit. A system of assisting in rotor speed control in a rotorcraft, the system can include: a computer having a control law, the control law operable to generate an increase collective command to an actuator in response to a rotor speed decreasing below a lower droop limit; wherein the lower droop limit is below a normal lower rotor speed range.

Abstract: The fundamental wind or water generator concept comprises one or more than one lift producing device(s), which, when subject to a wind or water current C, autonomously pivot(s) and translate(s) linearly while transmitting power to energy conversion unit (such as a pump or electric generator) by way of a flexible transmission member. The lift producing device(s) pivot(s) to a suitable angle, translate(s) a suitable distance, pivot(s) back to the original angle, and translate(s) back to its (their) starting position(s). This autonomous cycle continues indefinitely until the current's average velocity or direction changes substantially, at which point autonomous adjustments are made to accommodate the new conditions and, if possible, operation is resumed.

Abstract: A method of estimating an amount of undesired loading experienced by at least a portion of a structure (100) is provided. The structure (100) may be, for example, a wind turbine generator (WTG) and the portion for which undesired loading is estimated may be, for example, a rotor (130) of the WTG. The method includes receiving a first signal characterizing instantaneous stress experienced by a component (140) of the structure (100) and filtering out at least a portion of the received first signal that corresponds to the desired loading experienced by the component to produce a first filtered signal. The amount of undesired loading experienced by the at least a portion of the structure (100) is estimated based at least partially on the first filtered signal.

Abstract: The invention relates to an assembly and a method of fixing a rotor blade of a wind power plant. The wind power plant comprises a rotor blade, a pitch adjustment means, a bearing for the rotor blade and a brake disk.

Abstract: The invention relates to a method for monitoring a gearbox of a wind energy installation comprising. The invention further relates to a corresponding computer program product, a corresponding monitoring system for monitoring a gearbox of a wind energy installation and a corresponding wind energy installation.

Abstract: An alternative apparatus for utilizing wind and water energy on the basis of a cyclogyro rotor, which may be arranged as a small-size power plant, with increased efficiency and extended application spectrum. A turbomachine includes a substantially cylindrical rotor with the rotor body and a rotational axis, in which the rotor is arranged to be permeated in a direction perpendicularly to the rotational axis, and has a plurality of rotor blades arranged parallel to the rotational axis in the rotor body and an adjusting device for cyclically adjusting the rotor blades.

Abstract: A wind power turbine control method, the wind power turbine having an electric machine, in turn having a stator, a rotor rotatable about an axis of rotation with respect to the stator, and a mechanical bearing assembly configured to couple the rotor in rotary manner to the stator; the stator having at least one winding to interact electromagnetically with the rotor; and the control method including the steps of: estimating at least one quantity selected from a group including a distance between the rotor and the stator, the variation over time in the distance, and misalignment between the rotor and stator; defining a localized additional magnetic force as a function of the selected quantity; and regulating the selected quantity using the localized additional magnetic force defined.

Abstract: A method to individually optimize respective pitch angles of blades in a wind turbine. The method allows supplying (102) a modulation signal to modulate a pitch angle of the individual blade being optimized. The method further allows filtering (104) output power of the turbine subject to the modulating frequency to extract a power signal in a frequency spectrum including the modulating frequency. The extracted power signal and a demodulation signal are mixed (106) to generate a signal including a product of the extracted power signal and the demodulation signal. The generated signal is filtered (108) to remove the modulating frequency and extract a gradient signal effective to search a pitch angle estimate conducive to optimize output power of the turbine. The gradient signal may be integrated (110) to cause the gradient signal to converge towards an optimal pitch angle for the individual blade being optimized.

Abstract: A blade for a rotor of a wind turbine is divided into a root region closest to the hub and an airfoil region with a lift generating profile furthest away from the hub. A transition region has a profile gradually changing in the radial direction from the circular or elliptical profile of the root region to the lift generating profile of the airfoil region, and includes at least a first longitudinal segment extending along at least 20% of a longitudinal extent of the airfoil region. A base part has an inherent non-ideal twist, such as no twist, or a reduced twist compared to a target blade twist, so that an axial induction factor of the first base part at a design point deviates from a target axial induction factor. A number of flow altering devices are arranged so as to adjust the aerodynamic properties of the first longitudinal segment.

Abstract: A wind turbine blade is configured such that the lift force from the blade airfoil is always normal, or nearly normal, to the shaft torque. This condition maximizes energy conversion. This objective may be achieved by a) having the airfoil chord always aligned to the actual wind direction (subject only to small angle of attack variations), and b) slowing the turbine rotation rate so that no blade twist is needed. As a result, blade tip speed due to shaft rotation is less than the wind speed, and preferably much less. This low tip speed eliminates any hazard to birds. The lift force from the blade airfoil directly drives the torque on the shaft, so the control problem simplifies to adjusting the blade angle of attack to keep the lift constant across varying wind speeds.

Abstract: A method for repairing a rotor system (2) of a turbomachine, having a rotor (4) which has a groove (26) extending in the circumferential direction (58) of the rotor for accommodating an annular section (18; 28). The method has the following steps: chamfering a notch (40) in the groove (26); introducing a recess (44) into the groove (26); and inserting the annular section (18; 28) into the groove (26). At least one engagement element (48; 49) formed on the annular section (18; 28) engages in the recess (44) in order to form a lock against rotation in the circumferential direction (58).

Abstract: The invention provides a heat-dissipating system and a control method thereof. The heat-dissipating system has a plurality of fans and is configured for adjusting rotation-speeds of the fans. The control method includes following steps: obtaining a plurality of rotation-speed values of the fans; computing out a rotation-speed reference value according to the rotation-speed values; when the rotation-speed reference value is greater than a first threshold value, decreasing the rotation-speeds of the fans through a corresponding fan control signal; when the rotation-speed reference value is less than a second threshold value, increasing the rotation-speeds of the fans through the corresponding fan control signal.

Abstract: A wind turbine yaw system is provided that includes a yaw gear, at least two pinion gears, and at least two drive units, each of which is associated to one of the pinion gears for driving that pinion gear. The yaw system also includes a control system with a controller for generating a drive unit control signal for each drive unit for controlling the respective drive unit according to a reference signal having a desired operational parameter value for the respective drive unit, so as to realize the desired operational parameter value in the respective drive unit. The control system includes a feedback loop for each drive unit feeding a drive unit feedback signal including at least the actual value of one operational parameter of the respective drive unit back to the controller. The controller generates the drive unit control signals based on the reference signal and the feedback signals.

Abstract: The invention regards an apparatus for adjusting the yaw of a wind turbine adapted for mounting on a wind turbine comprising, a system for measuring the wind direction adapted, via a control signal, to control the yaw angle of the wind turbine based on the wind direction, and a wind sensor system adapted to determine the yaw error of the wind turbine, and means for modifying the control signal based on the yaw error determined by the wind sensor system.

Abstract: The present invention relates to a reinforced blade for a wind turbine, particularly to a blade having at least one elongated reinforcing member connected inside the shell for increasing the strength of the blade, each of the at least one elongated reinforcing member having a first end and a second end and extending in a longitudinal direction between the first end and the second end and wherein the first end is connected to the upper part of the shell and the second end is connected to the lower part of the shell thereby decreasing peeling and shear stresses in the trailing edge of the blade.

Abstract: This wheel comprises a plurality of vanes (2) arranged on a crown (3) and is equipped with a tip-forming member (10) attached to a central region (32) of the crown or hub of the wheel (1), radially inside the vanes (2), the crown defining a wet surface (31) for guiding a flow (E) passing between the vanes. The tip-forming member (10) is provided with at least one opening (121) for diverting a fraction (E1) of the flow towards the internal volume (V10) of this member. This member comprises a frustoconical annular skirt (11) and at least one fin (15) arranged in its internal volume (V10) and able to modify the path of the flow fraction (E1) entering this volume through the opening (121). This fin (15) extends as far as the edge (112) of the skirt (11) which defines an outlet opening (14) of the member (10) for the flow fraction (E1).

Abstract: A method for operating a machine located in choppy waters, in particular a wave energy converter, for converting energy from a wave movement of a fluid into another form of energy includes determining measurement variables at a first, relatively early time, and calculating a variable characterizing a wave movement expected at a second, later time on the basis of the determined measurement variables.

Abstract: A blade for a rotor of a wind turbine is divided into a root region closest to the hub and an airfoil region with a lift generating profile furthest away from the hub and a transition region. A base part of the transition region has an axial induction factor, which without flow altering device deviates at least 5% from a target axial induction factor. A number of first flow altering devices are arranged so as to adjust the aerodynamic properties of a longitudinal segment of the transition region to substantially meet the target axial induction factor.

Abstract: A control method for a wind turbine, in particular for a wind turbine blade is described. The control method makes use of the blade mode shapes, or natural vibration shapes, of the blade to detect the excitement level of the blade natural vibrations, and controls active lift devices on the blade in an effort to reduce the excitement levels, to reduce loading in the blade and the overall wind turbine structure. There is also provided a method of designing a wind turbine blade for use in such a method.

Abstract: The invention provides a shutdown controller for a wind turbine. To improve the estimation of a state of the wind turbine, the controller comprises at least two sensors being adapted to provide sensor data significant for different mechanical states in the wind turbine. The controller can provide an estimated state of the wind turbine based on the sensor data from the at least two sensors and compare the state of the wind turbine with a predefined detection limit to provide a shutdown signal if the estimated state is outside the detection limit.

Abstract: A method for operating a wind turbine with a variable speed rotor, a control system and a safety system, including the steps of initiating a braking procedure of the rotor of the wind turbine by the control system when the rotational speed of the rotor exceeds a first threshold value (nc1), and activating a safety system for braking the rotor when the rotational speed of the rotor exceeds a second threshold value (ns1) and when the control system has not initiated a braking procedure, the second threshold value (ns1) being greater than the first threshold value (nc1).

Abstract: A method of modifying an end wall contour is provided. The method includes creating a weld pool using a laser, adding a metal or a ceramic powder or a wire filler to the melt pool and modifying the part of the turbine in a manner that results in a change of about 0.005 to about 50 volume percent in the part of the turbine. The weld pool is created on a turbine component and contains molten metal or ceramic derived as a result of a heat interaction between the laser and the turbine component.

Abstract: An underwater turbine mounting includes a rigid tether having one end attached thereto at a pivot, and the other end adapted for connection to an underwater anchorage. The rigid tether is pivotable between a deployment condition and an anchorage condition. The mounting is pivotable between a deployment condition and an operating condition solely by adjusting the buoyancy thereof. The mounting is pivotable between an operating condition and a maintenance condition solely by adjusting the buoyancy thereof.

Abstract: A wind turbine comprises a hub, a blade rotatably mounted to the hub, and a pitch system. The pitch system includes a support, a first drive configured to rotate the blade relative to the support, a second drive configured to rotate the support relative to the hub. The support is configured to be selectively fixed relative to the blade and the hub such that the first or second drive may be used to pitch the blade. A method of pitch corresponding to this operation is provided.

Abstract: The present invention relates to a hydraulic pitch system for pitching a blade of a wind turbine having a hub by means of a hydraulic fluid. The system comprises at least one hydraulic cylinder for adjusting a pitch angle of the blade, the hydraulic cylinder comprising a pitch piston movable in the hydraulic cylinder, and a first port and a second port arranged on each side of the pitch piston, and an accumulator hydraulically connected to the cylinder. The system further comprises a pitch safety system adapted to maintain the blade in a predetermined pitch angle when a person is entering the hub of the wind turbine for service and/or maintenance, the pitch safety system comprising a first valve which by activation releases a pressure in the hydraulic pitch system by draining off the accumulator for the hydraulic fluid until the pressure has reached a predetermined pressure level.

Abstract: The present invention provides a method of operating a wind turbine having a rotor with a plurality of blades, a system for determining one or more loads on the wind turbine, a historical register of data on the wind turbine operation, and a control system for controlling one or more operational parameters of the wind turbine. The method comprises determining the loads on the wind turbine, and storing the determined loads on the wind turbine in the historical register. The method further comprises obtaining, from the historical register, a characteristic indicative of the loads on the wind turbine accumulated over time, and determining one or more wind thrust limits depending on the obtained characteristic indicative of the loads accumulated over time. One or more operational parameters of the wind turbine are controlled to keep the wind thrust on the wind turbine within the determined wind thrust limits.

Abstract: A propeller balancing device includes at least one stationary outer disc and a drive wheel arranged adjacent to the outer disc. The drive wheel includes magnets arranged at the periphery. A balancing weight is arranged in a groove formed in one of the outer disc or the drive wheel. A propeller including the propeller balancing device and a method of balancing a propeller are also disclosed.

Abstract: Apparatuses and methods are taught for cooling a turbine blade wherein at least one circuit is isolated along a cool suction side of the blade and the circuit turns aft toward a trailing edge.

Abstract: The present application provides a drive link for a constant-velocity joint of an aircraft rotor, the link connecting a drive hub attached to a driveshaft to a rotor yoke. The link comprises a leading bearing connected to the drive hub, a trailing bearing connected to the yoke, a central portion between the bearings, and a tension loop connecting the bearings. The tension loop is formed from a composite material and is formed as a continuous band. The tension loop transfers drive forces from the leading bearing to the trailing bearing for driving the yoke in rotation with the driveshaft.

Abstract: Various “contactless” bearing mechanisms including hydrodynamic and magnetic bearings are provided for a rotary pump as alternatives to mechanical contact bearings. In one embodiment, a pump apparatus includes a pump housing defining a pumping chamber. The housing has a spindle extending into the pumping chamber. A spindle magnet assembly includes first and second magnets disposed within the spindle. The first and second magnets are arranged proximate each other with their respective magnetic vectors opposing each other. The lack of mechanical contact bearings enables longer life pump operation and less damage to working fluids such as blood.

Abstract: A rotor dynamic balancing method for magnetic levitation molecular pump, includes activating an open loop feed forward control module after activating a motor of the magnetic levitation molecular pump; if the maximum radial vibration amplitude does not exceed ½ of a protective clearance during the acceleration of the rotor under the control of the open loop feed forward control module, indicating that the open loop feed forward control module is able to inhibit the co-frequency vibration of the rotor, so as to allow the rotational speed of the rotor to exceed its rigid critical rotational speed; and performing rotor dynamic balancing operation at a high speed by means of influence coefficient method. This method can directly perform rotor dynamic balancing operation with respect to the rotor at a high-speed, which facilitates the rotor dynamic balancing operation so as to perform the rotor dynamic balancing operation more quickly and efficiently.

Abstract: A gas turbine engine is disclosed having a thermoelectric device capable of changing a tip clearance in a turbomachinery component. In one non-limiting form the turbomachinery component is a compressor. The thermoelectric device can be used in some forms to harvest power derived from a waste heat. The tip clearance control system can include a sensor used to determine a clearance between a tip and a wall of the turbomachinery component.

Abstract: A system comprising a first wind turbine structure and a second wind turbine structure, wherein the first wind turbine structure and the second wind turbine structure are rotatable with respect to each other is provided. A safety bearing element is mounted to the first wind turbine structure such that the second wind turbine structure is in slideable contact with a contact surface of the safety bearing element if a distance between the first wind turbine structure and the second wind turbine structure is reduced below a predetermined reference value. The safety bearing element comprises an electrical indicating circuitry with an indicating conductor, wherein the indicating circuitry is connectable to a wear controller system such that a signal is generatable by the indicating circuitry and transmitted to the wear controller system until the indicating conductor is damaged due to the slideable contact of the second wind turbine structure with the safety bearing element.

Abstract: A gas turbine engine is disclosed having a thermoelectric device capable of changing a tip clearance in a turbomachinery component. In one non-limiting form the turbomachinery component is a compressor. The thermoelectric device can be used in some forms to harvest power derived from a waste heat. The tip clearance control system can include a sensor used to determine a clearance between a tip and a wall of the turbomachinery component.

Abstract: A wind-turbine gearbox system includes an input gear stage having mating gear surfaces finished to a surface roughness of less than 0.25 micron and at least one bearing supporting the input gear stage. A lubrication circuit is arranged to deliver lubricant to the input gear stage and the bearing during operation of the wind-turbine and includes an inline filter for removal of particles of less than 2 micron from the lubricant prior to delivery. A lubricant for use in the system may have a relatively low viscosity compared to conventional wind turbine gearbox lubricants.

Abstract: A rotary wing aircraft is provided including a dual counter-rotating, coaxial rotor system having an upper rotor system and a lower rotor system rotatable about a common axis. A plurality of blade assemblies is mounted to a portion of either the upper rotor system or the lower rotor system. A plurality of individually controllable actuators is coupled to each of the plurality of blade assemblies. Each of the plurality of actuators is configured to control movement of the coupled blade assembly about a pitch axis. The rotary-wing aircraft additionally includes a sensor system within an airframe. A higher harmonic control (HHC) controller is arranged in communication with the sensor system and the plurality of actuators to individually control the upper rotor system and the lower rotor system to reduce vibration.

Abstract: A motor assembly that includes a motor having a motor casing, a rotatable shaft extending from said motor casing to a shaft length and a hub coupled to said rotatable shaft, the hub having a circumferential skid surface disposed immediately proximal to the motor casing and having a channel configured to seat a propeller, when a propeller is present, wherein a bending moment applied to the shaft through the hub results in the circumferential skid surface contacting said motor casing.

Abstract: An electronic device includes a fan and a control device for controlling the fan. The control device includes a control unit, a first signal generation unit and a second signal generation unit each connected to the fan. The control unit has a first signal output terminal and a second signal output terminal. In use, the control unit first enables the first signal output terminal to generate a speed adjusting signal to control the fan. The control unit further detects whether a speed measurement signal is received from the fan, and enables the second signal output terminal to generate the speed adjusting signal to control the fan, if no speed measurement signal is received.

Abstract: A rotating fan with a transmission mechanism and a blade deployment mechanism. In an energized state, an electromagnetic coil generates a magnetic force that causes a clutch plate to be in contact with a contact surface, thereby engaging a planetary gear system. In a de-energized state, the clutch plate is not in contact with the contact surface, thereby disengaging the planetary gear system. In a deployed configuration, a drive link activated by the planetary gear system rotates a blade link to cause a fan blade to pivot. The result is that the fan blade tip is farther from the motor shaft than the fan blade root. In a retracted configuration, the drive link rotates the blade link to cause the fan blade to pivot and retract. The result is that the fan blade tip is equidistant from the motor shaft as the fan blade root.