Abstract: A hollow-cast casting is provided, which includes at least one core opening that is caused by the production technique and which has a closure device that closes the core opening. The closure device can be inserted into the core opening axially in relation to the core opening and provides at least one surface region which, in axial projection in relation to the core opening, can be made to abut a surface region of the casting that is facing toward the casting. The surface region lies radially outside a cross-sectional area predetermined by the core opening.

Abstract: A method for monitoring operating parameters of a rotating blade is provided. The blade includes at least one sensor thereon, the sensor operatively coupled to a data acquisition device. The method includes transferring data from the sensor to the data acquisition device, the data relating to blade acceleration measurements, transmitting a signal representative of the transferred data from the data acquisition device to a control system, and controlling blade loads using the transmitted signal.

Abstract: An arrangement for detecting bending deflection of a wind turbine blade is provided. The arrangement for the wind turbine includes a radio transmitter and a linear antenna array assigned to the radio transmitter. The radio transmitter is mounted on the blade tip and emits a signal. The antenna array is mounted on the rotor of the wind turbine in a co-rotating manner and receives the signal. On the basis of the transit times of the signal from the rotor to the individual antennas of the array, the position of the radio transmitter relative to the array is determined. In the event of blade deflection, for example when a high wind load is present, the relative position changes which is detected by the arrangement.

Abstract: A system is disclosed. The system includes a processing subsystem that determines preliminary voltages corresponding to a plurality of blades based upon blade passing signals (BPS), and generates a plurality of clearance values by normalizing the preliminary voltages for effects of one or more operational parameters, wherein the plurality of clearance values are representative of clearance of the plurality of blades.

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: The current invention provides significant performance improvements or significant energy savings for fans used in these applications: personal, industrial and automotive cooling, ventilation, vacuuming and dust removal, inflating, computer component cooling, propulsors for unmanned and manned air vehicles, propulsors for airboats, air-cushion vehicles, airships and model aircraft. Additionally, the invention provides higher performance such as higher lift and higher lift efficiency to small air vehicles. These advantages are achieved by using plasma actuators to provide active flow control effectors into thin fan blades and wing.

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: The invention relates to a method for improving the heat resistance of a resistive element embedded in an alumina deposit covering a surface of a substrate, the alumina deposit comprising a surface portion and a deep portion which is sandwiched between the surface portion and the surface of the substrate and in which the resistive element is located, which method is characterised in that it comprises a densification of the surface portion of the alumina deposit. Field of application: any field in which an evaluation of the deformation of mechanical parts intended to be exposed to very high temperatures, by means of resistive elements of the strain gauge type, is necessary, and in particular the design of engine parts in the aeronautics field of the turbine blade type.

Abstract: A sensor system for measuring aerodynamic loads acting on a wind turbine rotor blade is disclosed. The measured aerodynamic loads can be converted to an angle of attack of the resulting wind which flows past the moving rotor blade. The sensor is realized as a trailing edge flap which is elastically moveable relative the main part of the wind turbine blade. By measuring motion of the trailing edge flap or corresponding motions of components of the sensor system, the aerodynamic forces acting on the blade can be determined. Due to the relative small dimensions of the sensor flap and the relative small displacements of the flap, the sensor system only affects the aerodynamic properties insignificantly.

Abstract: A system and associated method for detecting lighting strikes on a wind turbine uses a plurality of lightning strike conductors that are connected to any combination of the wind turbine components. A common ground cable is connected to the conductors and to a wind turbine grounding system. A sensor is operatively configured on the common ground cable to detect current flowing through the cable from a lightning strike incident on any one of the receptors, with the sensor producing a signal proportional to the intensity of the lightning strike.

Abstract: A vibration-resistant wind turbine and process for operation is provided. The wind turbine has a rotor with at least two blades, each of which includes an inclinometer arrangement with at least two axes, and an evaluating unit. The evaluating unit determines the bending and/or twisting of the blade relative to the longitudinal axis of the blade on the basis of signals from the inclinometer arrangement for each blade during operation. Each rotor blade further has at least one liquid tank which is capable of receiving or transferring liquid from or to a liquid reservoir via a transfer mechanism in response to the determined bending and/or twisting of the rotor blades to reduce vibration caused by imbalances, thereby extending the service life of the wind turbine.

Abstract: A pitch drive system for a wind turbine includes a pitch drive motor, a first position detector, a driver, a second position detector, and a controller. When the blades rotate to a mechanical zero position, a position value detected by the first position detector is a first zero point position value. The driver is operable to store the first zero point position value. When the blades rotate to the mechanical zero position, a position value detected by the second position detector is a second zero point position value. The controller is operable to store the second zero point position value. When a corresponding back up command is received, the first zero point position value stored in the driver is backed up into the controller, and the second zero point position value stored in the controller is backed up into the driver respectively.

Abstract: A blade tracking system including a detector having one or more sensors to detect radiation from at least one field of view of the detector, the one or more sensors generating signals based on changes in incident radiation to the one or more sensors as a rotor blade passes the field of view, and a processor to determine a pass time for the rotor blade to pass through the at least one field of view based on the generated signals.

Abstract: A load control system for a wind turbine and a method for controlling wind turbine loading are provided. The system includes a sensor assembly. The sensor assembly includes a light source mounted to a rotor shaft and configured to emit a light, and a sensor mounted to the rotor shaft and configured to sense the light and measure a location of the light in a plane perpendicular to a longitudinal axis. The system further includes a controller communicatively coupled to the sensor assembly.

Abstract: Methods, apparatus, and products are disclosed for improving the airflow exiting a blower that has one or more adjustable guide vanes that are affixed to the blower at one or more pivot points located in an outlet of the blower that include: determining a rotational speed of an impeller in the blower and adjusting a position of at least one of the adjustable guide vanes in dependence upon the rotational speed of the impeller.

Abstract: A technique is provided for operating a wind farm at increased rated power output. The technique includes sensing a plurality of operating parameters of the wind turbine generator, assessing the plurality of operating parameters with respect to respective design ratings for the operating parameters, and intermittently increasing a rated power output of the wind turbine generator based upon the assessment.

Abstract: A maintenance apparatus is provided for use with a wind turbine that has a tower, a hub supported by the tower, and a plurality of blades extending outwardly from the hub. The maintenance apparatus has a mounting element that is configured to be secured to the tower and to be selectively movable along the length thereof. A robotic arm is coupled to the mounting element, and a blade-engaging device is coupled to the robotic arm and is configured to engage one of the blades to effect a maintenance task thereon.

Abstract: Methods, apparatus, and products are disclosed for improving the airflow exiting a blower that has one or more adjustable guide vanes that are affixed to the blower at one or more pivot points located in an outlet of the blower that include: determining a rotational speed of an impeller in the blower and adjusting a position of at least one of the adjustable guide vanes in dependence upon the rotational speed of the impeller.

Abstract: A control method of a fan comprises steps of detecting a rotational speed of a blade and a rotor position of the blade; generating a control signal according to the rotational speed and a predetermined rotational speed; obtaining a Back-EMF waveform according to the control signal, the rotational speed, the rotor position and a waveform; adjusting the phase of the Back-EMF waveform; and outputting a switch control signal.

Abstract: A method and system for establishing sets of blade frequency values for each rotating blade of a rotor assembly at two or more different points in time and determining an indication of blade health from the change in the blade frequency values is provided. Blade frequency values are determined by receiving measurements of vibratory responses from blade monitoring equipment (20) and processing via a processing device (30) vibration data as a system of rotating blades to extract a frequency of each blade. Sets of blade frequency values are compared to determine a change in the blade frequency values for each rotating blade to provide the indication of blade health.

Abstract: A system for detecting defects in a turbine rotor blade of a combustion turbine engine. The system may include: a turbine rotor blade that includes an insulator coating; a first electrode that is electrically connected to the turbine rotor blade; a second electrode that resides in proximity to the turbine rotor blade; means for inducing a voltage across the first electrode and the second electrode; and means for detecting current flowing between the first electrode and the second electrode.

Abstract: An arrangement with a nacelle and an instrument bar is provided. The instrument bar is arranged on top of the nacelle. A rotational axis interacts with the nacelle and with the instrument bar. The rotational axis is constructed and arranged such that the instrument bar is allowed to pivot between a first position and a second position in reference to the top side of the nacelle. The instrument bar projects above the top side of the nacelle when locked in the first position, while the instruments are operated. The instrument bar is locked close to the top side of the nacelle in the second position to allow access to the instruments.

Abstract: Systems and methods are provided for real-time detection of the onset of stall in turbomachinery, such as compressor stall. The methods are capable of detecting and analyzing time of arrival of the chord of the blade at a sensor array to provide an indication of the onset of compressor stall. Systems for detecting the onset of compressor stall include: light sources; a plurality of linearly arranged optical fibers for transmitting light from the light sources and for receiving transmitted light reflected from a blade; a detector for measuring intensity of the reflected light; and a processor for analyzing the intensity of the reflected light to determine blade twist angle and from the blade twist angle identify onset of compressor stall. The invention can prevent the needless loss of life and assets caused by compressor stall that may lead to unexpected catastrophic failure of an engine.

Abstract: A method is provided for controlling the pitch systems of a plurality of pitch systems of a wind turbine. The method includes generating a main pitch control signal for the pitch systems on the basis of a performance parameter of the wind turbine and generating a distinct auxiliary pitch control signal for each individual pitch system of the plurality of pitch systems. The method further includes adding an auxiliary pitch control signal to the main pitch control signal to give a combined pitch control signal for a pitch system. The method then includes controlling that pitch system in response to that combined pitch control signal wherein an auxiliary pitch control signal is suppressed when a pitch activity value and/or a pitch variation value is below a predefined threshold.

Abstract: A device adapted to be fitted with propeller blades includes a first retention ring including over a periphery thereof a plurality of radial bores; and a second retention ring including over a periphery thereof a plurality of radial bores, the first and second retention rings being mounted one on top of the other in the radial direction, each bore in the first retention ring being positioned opposite a bore in the second retention ring, a bore in the first retention ring arranged opposite a bore in the second retention ring forming a bore pair adapted to receive a foot of a blade.

Abstract: A sensor device for measuring aerodynamic loads of a rotor blade for a wind power installation . The sensor device includes a reflector arranged in a cavity of the rotor blade which signals a signal evaluation device arranged at a distance from the reflector. The signal evaluation device detects and quantifies physical changes of the rotor blade from the reflected signal. A cleaning device for the reflector is arranged on the reflector for activation by a centrifugal force generated during the rotation of the rotor to clean the reflector.

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: A system and method for automatically inspecting a lightning protection system on a wind turbine is disclosed. The system and method may include a wind turbine having a plurality of blades mounted to a hub, a lightning receptor on each of the plurality of blades, a lightning protection system extending from each of the lightning receptor to an earth grounding grid and a conductor that is part of a testing system extending from at least inside the hub, through the inside of at least one of the plurality of blades and connecting to the lightning receptor, the conductor completing a circuit extending from the lightning receptor to the earth grounding grid. A test current signal may be introduced into the testing system for a leg of the lightning protection system to be tested and an electrical continuity in the circuit using the test current signal may be determined.

Abstract: The lengths and/or chords and/or pitches of wind turbine or propeller blades are individually established, so that a first blade can have a length/chord/pitch that is different at a given time to the length/chord/pitch of a second blade to optimize performance and/or to equalize stresses on the system.

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 ceramic matrix composite blade for use in a gas turbine engine having an airfoil with leading and trailing edges and pressure and suction side surfaces, a blade shank secured to the lower end of each airfoil, one or more interior fluid cavities within the airfoil having inlet flow passages at the lower end which are in fluid communication with the blade shank, one or more passageways in the blade shank corresponding to each one of the interior fluid cavities and a fluid pump (or compressor) that provides pressurized fluid (nominally cool, dry air) to each one of the interior fluid cavities in each airfoil. The fluid (e.g., air) is sufficient in pressure and volume to maintain a minimum fluid flow to each of the interior fluid cavities in the event of a breach due to foreign object damage.

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: An apparatus is described for measuring the deposition of ice on the rotor blades (5) of a wind turbine (1), having a transmitting and receiving device with parts that are on the rotor blades (5) on the one hand and parts that are arranged in fixed positions and are connected to each other via a wireless transmission link on the other and having an evaluation circuit (9) connected to the transmitting and receiving device. In order to provide advantageous structural conditions, it is proposed that the transmitting and receiving device comprises passive transponders (6) on the rotor blades (5) and at least one stationary reader unit (7) for the transponders (6) and the evaluation circuit (9) has a comparator stage (10) for the minimum transmission output of the reader unit (7) required to read the transponders (6) reliably, with a programmable threshold value for this transmission output in the event of the deposition of ice.

Abstract: In one aspect, a system for detecting loads transmitted through a blade root of a rotor blade of a wind turbine is disclosed. The system may include a root attachment assembly configured to couple the blade root to a hub of the wind turbine. The root attachment assembly may include a barrel nut mounted within a portion of the blade root and a root bolt extending from the barrel nut. In addition, the system may include a sensor associated with the root attachment assembly. The sensor may be configured to detect loads transmitted through at least one of the barrel nut and the root bolt.

Abstract: A clearance sensing system for a rotating machine includes a plurality of sensor probes disposed within a stationary shroud of the rotating machine. Each of the plurality of sensor probes is adapted to measure a parameter indicative of an axial and a radial displacement of a rotating component within the shroud and to produce a signal that corresponds to the parameter. In certain embodiments, this parameter may include a capacitance between the rotating component and the sensor probe. The clearance sensing system further includes a circuit that receives the signal from each of the plurality of sensor probes and determines (a) the axial displacement of the rotating component within the shroud and (b) a radial displacement of the rotating component relative to the shroud.

Abstract: A method and a system for controlling operation of a wind turbine are provided. The method includes determining at least one failure mode relating to one or more components of the wind turbine, estimating a remaining lifetime of the component under current operating conditions, determining one or more control schemes to control the operation of the wind turbine in order to adjust the remaining lifetime of the component to a desired remaining lifetime of the component, determining a power production yield for the determined one or more control schemes and selecting a determined control scheme for controlling the operation of the wind turbine that maximizes the power production yield.

Abstract: A system for identifying the likelihood of a wind turbine rotor blade striking a wind turbine tower comprises a device for sensing bending of a wind turbine rotor blade and a device for sensing bending of a wind turbine tower. In a preferred embodiment Long Period Grating (LPG) sensors are used to measure bending of the tower. Preferably a plurality of LPG sensors is provided along the length of the blade. In one embodiment at least one of the LPG sensors comprises two sensing elements arranged to sense in perpendicular directions. In another embodiment a plurality of LPG sensors are provided each on different sides of the wind turbine tower. A processor uses the sensed blade and tower bending to determine whether the distance between the blade and the tower will be below a predetermined minimum value.

Abstract: The present technology relates generally to a device for the detection of a shaft fracture in a rotor of a turbine, for example a medium pressure turbine such as a gas turbine, in particular an aircraft engine, whereby at least one stator-side sensor element is positioned downstream from the turbine in the area of a stator-side guide vane ring of another turbine in particular, a low pressure turbine; and whereby a radially inner section of the last rotor-side moving blade ring (as seen in the direction of flow) of the turbine cooperates with at least one sensor element directly and/or proximally in the event of a shaft fracture in the rotor of the turbine to generate an electric signal corresponding to the shaft fracture.

Abstract: A method for cleaning deposits from a wave energy converter includes driving at least one rotatably mounted component that is coupled to an energy converter. The energy converter is configured to convert energy from wave motion of a fluid into a different form of energy. A negative energy balance of the wave energy converter is present during the cleaning over an average period of time.

Abstract: A wind turbine blade extending along a longitudinal axis from a root end to a tip end and in a transverse plane perpendicular to the longitudinal axis, the transverse plane having a main axis extending through an elastic center point, wherein the wind turbine blade comprises a sensor system including a first sensor set for measuring a first bending moment in a first sensor position at a first distance from the root end, the first sensor set comprising a first primary sensor for measuring a primary component and a first secondary sensor for measuring a secondary component, wherein a first primary sensor axis in the transverse plane is oriented in a direction defined by the first primary sensor and the elastic center point, and a first secondary sensor axis in the transverse plane is oriented in a direction defined by the first secondary sensor and the elastic center point, and wherein an angle between the first primary sensor axis and the first secondary sensor axis is in the range from 50° to 130°

Abstract: A method for determining a bending angle of a rotor blade of a wind turbine system includes step of reading in an acceleration signal which represents an acceleration of the rotor blade acting essentially perpendicularly with respect to a rotor plane. In addition, the method includes a step of determining the bending angle of the rotor blade of the wind turbine using the acceleration signal.

Abstract: A system, a device and a method for controlling an operation of a wind turbine (100) based on a wind turbine component workload. The system includes a control device (120) that is configured to actuate a wind turbine component (130). The system also includes a wind turbine controller (205) that is coupled in communication with the control device (120) and configured to determine a workload associated with the wind turbine component (130) based at least in part on one or more actuations of the wind turbine component (130) by the control device (120) within a time period. The wind turbine controller (205) is also configured to calculate an operating threshold value based at least in part on the calculated workload and to operate the wind turbine component (130) by the control device (120) based on the calculated operating threshold value.

Abstract: An impeller device may include a magnetic detecting element and a magnetic body, which is paired with the magnetic detecting element, for detecting a rotational position of a rotary impeller. The rotary impeller is formed with a bottomed recessed part having an opening into which one of the magnetic detecting element or the magnetic body is inserted, and the opening of the recessed part is sealed with resin injected by insert molding so that the one of the magnetic detecting element and the magnetic body is buried in the rotary impeller. The magnetic detecting element and the magnetic body are capable of facing to each other through a bottom face of the bottomed recessed part.

Abstract: A method includes obtaining at least one operational parameter value and at least one environmental parameter value associated with a wind turbine, predicting a future speed of the wind turbine based upon the at least one operational parameter value and the at least one environmental parameter value, determining whether the predicted future speed of the wind turbine exceeds a threshold speed, and if the predicted future speed of the wind turbine exceeds the threshold speed, controlling the wind turbine so that an actual future speed of the wind turbine does not exceed the threshold speed.

Abstract: A wind power rotor with measuring device (3) for measuring rotor deflection. A measuring cavity (20), which has a transmitter/receiver (31/32) at one end and a reflector device (33) at the other end, extends in a longitudinal direction of the rotor. The transmitter/receiver (31/32) is accommodated in a housing (50), which is fastened to an intermediate plate (10) with three-point mounting (12, 13, 14).

Abstract: A system for the structural monitoring of blades 1 on a wind turbine. Each blade 1 has respective optical fiber bragg grating sensors 5. The system has a number of input connectors, which connect to the strain sensors 5 of respective blades 1. A single output connector connects to a data processing device 3 which processes signals from the strain sensors 5. The input connectors each have a signal path to the output connector that is different in length to the signal path from the other input connectors, such that signals from a given blade 1 can be identified at the data processing device 3 by the time of arrival of the signals. The system has the advantage that the each of the blades 1, including the sensors attached to it or embedded within it can be identical and therefore interchangeable.

Abstract: Systems and methods for determining thrust on a wind turbine are disclosed. In one aspect, a system is described that can be comprised of a wind turbine comprising a rotor, wherein one or more rotor blades of the wind turbine are affixed to the rotor; and one or more sensors located on or within the rotor, wherein the one or more sensors measure deflection of the rotor. In one aspect, the measured deflection is correlated with thrust on the wind turbine and the measured thrust can be used to determine at least in part a pitch angle for at least one of the one or more rotor blades during peak shaving.

Abstract: Method and blade monitoring system for monitoring bending moment of a wind turbine blade. The method comprises obtaining a first sensor set signal indicative of a first bending moment at a first sensor position different from the tip end along the longitudinal axis of the wind turbine blade, and estimating a bending moment at a first estimation position along the longitudinal axis based on the first sensor set signal, wherein the first sensor position is different from the first estimation position along the longitudinal axis. The blade monitoring system comprises a processing unit and an interface connected to the processing unit, the processing unit being configured for performing the method.

Abstract: A wind power generating system in which a plurality of stationary modules form a toroidal shaped tower that accelerates wind passing around and between the modules due to the Bernoulli Effect. Between the modules are located a plurality of vertical axis wind turbine rotors with an integrated generator system that in combination forms an integrated rotor and generator assembly connected to a rotatable yaw platform via an improved support arm. The rotor and generator assemblies act independently of each other to accommodate different wind conditions at different altitudes and to provide partial production to significantly enhance overall wind production.