Abstract: A wind turbine is provided, including a hub, rotor blades, wherein each rotor blade is rotatably supported at or in the hub by a pitch bearing, a pitch control device for changing a pitch angle of the rotor blades, and a measurement system for capturing a sensor signal in or at the pitch bearing and for changing the pitch angle by the pitch control device as a function of the sensor signal to prevent failure of the pitch bearing due to a lack of lubrication, wherein the sensor signal represents a change in vibration, noise and/or temperature in or at the pitch bearing. Due to the fact that the pitch angle can be changed as a function of the sensor signal, lubrication of the pitch bearing is ensured throughout the lifetime of the pitch bearing. Unnecessary pitch movements can be prevented.

Abstract: Provided is a wind turbine and to a method and a device for controlling aerodynamic properties of a blade of the wind turbine, the blade including a predetermined number of add-on members which are actuated by a corresponding trim actuator to alter the aerodynamic properties of the blade, wherein each trim actuator is configured to hold the add-on member in a predetermined first position and a predetermined second position. The control device is configured to determine a first number of add-on members which are to be held at the predetermined first position, and to determine a second number of add-on members which are to be held at the predetermined second position.

Abstract: A vibration control system for a rotor hub provides vibration attenuation in an aircraft by reducing the magnitude of rotor induced vibratory. The system can include a force generating device attached to a rotor hub which rotates along with the rotor at the rotational speed of the rotor. Vibratory shear force is generated by rotating unbalanced weights each about an axis non-concentric with the rotor hub axis at high speed to create large centrifugal forces. The rotational speed of the weights can be a multiple of the rotor rotational speed to create shear forces for canceling rotor induced vibrations. The amplitude of the generated shear force is controlled by indexing the positions of the unbalanced weights relative to each other, while the phase of the shear force is adjusted by equally phasing each weight relative to the rotor.

Abstract: There is provided a method (40) of correcting blade pitch in a wind turbine (10) having a tower (12) and a plurality of rotor blades (18). The method (40) comprises: receiving (410) sensor output data from one or more wind turbine sensors (141), the sensor output data including data indicative of excitation of the tower (12) for a plurality of different pitch angles of a particular one of the blades (18); determining (420) a corrected pitch reference of the particular blade (18), the corrected pitch reference corresponding to a minimum tower excitation based on the received sensor output data; and, sending (430) the corrected pitch reference to a pitch actuator system (24) of the particular blade (18).

Abstract: A method is used to identify impending or previously occurring condensation on/in electric motors, in particular on/in electric motors as a component of fans or fan groups. It includes the following method steps: Determining component temperatures, preferably surface temperatures on the electronics, on/in the motor, on/in the fan, or on/in fan groups; Determining the dew point temperature or individual dew point temperatures on the electronics, in/on the motor, fan, or on/in fan groups; Comparing the respective component temperature with the respective dew point temperature and concluding a formation of condensation has already taken place or is imminent when the component temperature approaches the dew point temperature or when the dew point temperature is undershot. A further method serves to prevent the formation of condensate and/or to eliminate/remove condensate on/in electric motors, in particular on/in electric motors as a component of fans or fan groups.

Abstract: A method of controlling a plurality of wind turbines of a wind park includes: determining an axial induction zone of at least a wind turbine of the wind park; and modifying the axial induction zone for controlling wind farm blockage by adjusting at least one of the following operational variables: a yaw angle of a blade rotor of the wind turbine, a pitch offset angle of at least one blade of the blade rotor, a rotor speed of the blade rotor.

Abstract: The present disclosure relates to a method for operating a wind power installation, to an associated wind power installation and to a wind farm. The method comprises the following steps: determining at least two, preferably at least three and particularly preferably all the environmental parameters of the environment of the wind power installation selected from the list consisting of: turbulence intensity, air density, air temperature and shear; providing boundary conditions for operating the wind power installation, the boundary conditions containing at least one from a load boundary condition, a noise level boundary condition and a power boundary condition; adapting an operational control, in particular an operating point and/or an operating characteristic, of the wind power installation on the basis of a combination of the changes in the determined environmental parameters taking into consideration the boundary conditions.

Abstract: A drive arrangement for a cycloidal marine propulsion unit including at least two electrical blade motors each associated to a respective blade for pivoting thereof, each blade motor being operationally coupled to a respective blade drive for actuating the corresponding blade motor. The at least two blade drives each include a respective blade drive power converter operationally coupled to a first common intermediate DC-link, wherein the at least two blade drives being configured to feed power from the first common intermediate DC-link to their respective blade motors, and to feed regenerative power from their respective blade motors to the first common intermediate DC-link. The disclosure also concerns a marine propulsion unit having such a drive arrangement, and a method of operating such a drive arrangement.

Abstract: A method for detecting and reducing edgewise vibrations in a rotor blade of a wind turbine includes, for a given wind speed, determining a frequency or frequency band at which edgewise vibrations are producible in the rotor blade. The method determines an electrical characteristic of the pitch actuator that correlates to an increased torque required to hold a pitch angle of the rotor blade constant at the frequency or frequency band. During an operational power-production mode of the wind turbine, the electrical characteristic of the pitch actuator is monitored. Upon the electrical characteristic reaching a predefined limit value indicative of edgewise vibrations in the rotor blade, corrective action is initiated by the wind turbine controller to reduce or prevent the edgewise vibrations.

Abstract: A method for detecting actual slip in a coupling of a rotary shaft, for example, in a wind turbine power system, includes monitoring, via a controller, a plurality of sensor signals relating to the coupling for faults. In response to detecting a fault in the plurality of sensor signals relating to the coupling, the method includes determining, via the controller, whether the fault is indicative of an actual slip or a no-slip event of the coupling using one or more classification parameters. When the fault is indicative of the actual slip, the method includes estimating, via the controller, a magnitude of the actual slip using the plurality of sensor signals and a time duration of the actual slip. Further, the method includes implementing, via the controller, a control action based on the magnitude of the actual slip in the coupling.

Abstract: A tower structure of a wind turbine includes a plurality of tower sections stacked atop each other in an end-to-end configuration along a vertical axis to form the tower structure of the wind turbine at a wind turbine site. Each of the tower sections is formed of at least one first tubular portion and at least one second tubular portion. Further, the first and second tubular portions of each of the plurality of tower sections are concentric with each other. Moreover, the first tubular portion is formed at least in part, of a cementitious material and the second tubular portion is formed of a perforated material having a plurality of holes.

Abstract: Provided is a root portion of a wind turbine blade for a wind turbine, whereby the root portion includes multiple first bolts arranged within the root portion and extending out of a root attachment face of the root portion for attachment of the root attachment face to a bearing or a hub flange, and whereby the root portion includes multiple first connectors fixedly arranged within the root portion, wherein the multiple first bolts are connected to the root portion by the first connectors for transmission of force from the multiple first bolts to the root portion via the multiple first connectors, whereby the first connectors are arranged in a first row along the root portion and each of a multiple of second connectors is fixedly arranged within the root portion and in a second row along root portion.

Abstract: A detuner system for a wind turbine includes a drive train component having a natural frequency. The drive train component is configured to rotate about an axis of rotation at a range of different speeds. The detuner system includes a controller for selectively interacting with the drive train component and cause a step change in the natural frequency of the drive train component at a first threshold of the rotational speed range, and cause a step change in the natural frequency of the drive train component at a second threshold of the rotational speed range different to the first threshold.

Abstract: This invention relates to a method and a wind turbine blade, wherein one or more airflow modifying devices are attached to a wind turbine blade having a base aerodynamic profile. The base aerodynamic profile is configured to substantially carry the structural loading of this modified wind turbine blade. The airflow modifying device is manufactured via 3D-printing and/or via 3D-machining and optionally coated or laminated before attachment. Once attached, the airflow modifying device may further be coated or laminated before working the outer surfaces into their finished shape.

Abstract: Provided is a wind turbine rotor blade flow guiding device that includes a first portion including a rear surface for facing a surface of a wind turbine rotor blade and a second portion connected to the first portion and extending from the first portion in a first direction along a length, the second portion including a top surface angled at an angle between 90° and 180° with respect to the rear surface of the first portion. The second portion includes a plurality of corrugations extending along the length. The second portion further includes a plurality of openings configured to allow a flow to pass through the second portion. Further disclosed is a wind turbine and a wind turbine rotor blade each including the wind turbine rotor blade flow guiding device.

Abstract: A method for detecting and controlling whirling oscillations of the blades of a wind turbine is presented. The detection of the whirling oscillations is based on measurement signal indicative of blade oscillations, and a rotation transformation of the measurement signal from a measurement frame into at least one target frame based on the whirling oscillation frequency. The rotation-transformation comprises a backward or forward rotation transformation direction relative to a rotor rotation direction. The control is based on an oscillation component obtained from the rotation-transformed measurement signal where the oscillation component is indicative of the whirling oscillation in the backward and/or forward rotation direction.

Abstract: There is provided a rotor bow mitigation system and method for an aircraft engine. At least one value of at least one engine parameter prior to a shutdown of the engine is obtained, the at least one engine parameter comprising a first temperature internal to the engine. A second temperature external to the engine is measured and a motoring duration and a motoring interval for the engine are determined based on at least the first temperature and on the second temperature. Upon detecting a start indication for the engine, the engine is motored for the motoring duration and at the motoring interval.

Abstract: In an embodiment, a duct for a ducted-rotor aircraft includes a hub, the hub including a rotor and one or more motors configured to drive the rotor. The duct also includes a duct ring that defines an opening surrounding at least a portion of the hub. The duct also includes a plurality of stators that extend outward from the hub. The duct also includes at least one battery electrically coupled to the rotor and configured to power the one or more motors.

Abstract: A wind turbine drive system includes a plurality of drive devices, a state quantity detection unit, and a control unit. The plurality of drive devices are provided in a first structure (a nacelle), and a ring gear is provided in a second structure (a tower). Each of the drive devices includes a motor drive portion, a speed reducing portion, and a motor braking portion for braking the motor drive portion. The state quantity detection unit detects a load between a meshing portion of each of the drive devices and the ring gear. Based on the thus detected load for the each of the drive devices, the control unit controls at least one of the motor drive portion and the motor braking portion so as to reduce a degree of variation in the load among the drive devices.

Abstract: Provided is a method for operating a wind turbine, an associated wind turbine and a wind park. The method comprises a) providing an indicator for the occurrence of a flow separation on a pressure side of a rotor blade of a rotor of the wind turbine, and b) changing an operational management of the wind turbine using the indicator, wherein the indicator comprises a pitch angle of the rotor blade. By using the pitch angle as an indicator, a flow separation on the pressure side of the rotor blade can be effectively prevented.

Abstract: The present invention relates to a damper unit for damping oscillations of a tower structure when secured thereto, the damper unit comprising a damper unit structure adapted for attachment to the tower structure, a pendulum structure, a suspension arrangement for suspending the pendulum structure from the damper unit structure such that the pendulum structure is allowed to displace from a neutral position for the pendulum structure, the suspension arrangement comprising one or more wires for suspending the pendulum structure, a sensor adapted for measuring oscillations of the tower structure, and tuning means configured for adjusting the natural frequency of the suspended pendulum structure in response to measured oscillations of the tower structure. The present invention further relates to an associated method.

Abstract: A system and method are provided for controlling a wind turbine. Accordingly, a controller of the wind turbine determines a thermal gradient of the tower due to solar heating. The controller also determines a displacement of a reference point of the wind turbine from a nominal position resulting from a thermal expansion of a portion of the tower. The displacement includes a displacement magnitude and a displacement direction. The displacement direction is in a radial direction opposite of a maximal peak of the thermal gradient. Additionally, the controller determines a correction factor corresponding to the displacement and a setpoint for a component of the wind turbine based, at least in part, on the correction factor. Finally, an operating state of the wind turbine is established based, at least in part, on the setpoint.

Abstract: A propeller control unit (PCU) has: a pitch angle actuator; a valve operable to selectively fluidly connect the pitch angle actuator with a source of oil for controlling pitch angles of blades of a propeller and with a drain line for draining oil out of the pitch angle actuator for feathering the blades; and a bypass line having an inlet hydraulically between the valve and an inlet of the drain line, the bypass line having an outlet hydraulically between the inlet of the drain line and an outlet of the drain line.

Abstract: Systems and methods for harnessing hydro-kinetic energy. The system includes a single central axle, a plurality of vanes, and a generator. The plurality of vanes may be configured to rotate about the central axle. Each vane may include a frame and a panel rotatably attached the frame. The panel may comprise a plurality of channels having a C-shaped cross-section. Movement of surrounding water may cause the panel to rotate relative to the frame between an open and closed position. The generator may be configured to convert the rotational motion of the plurality of vanes into electrical energy.

Abstract: An intentional fluid manipulation apparatus (IFMA) assembly with a first thrust apparatus that imparts a first induced velocity to a local free stream flow during a nominal operation requirement. The first thrust apparatus creates a streamtube. A second thrust apparatus is located in a downstream portion of the streamtube. The second thrust apparatus imparts a second induced velocity to the local free stream flow. The second induced velocity at the location of the second thrust apparatus has a component in a direction opposite to the direction of the first induced velocity at the location of the second thrust apparatus.

Abstract: An apparatus and method an engine component for a turbine engine comprising an outer wall bounding an interior and defining a pressure side and an opposing suction side, with both sides extending between a leading edge and a trailing edge to define a chord-wise direction, and extending between a root and a tip to define a span-wise direction, at least one cooling passage located within the interior, a set of cooling holes having an inlet fluidly coupled to the cooling passage, an outlet located on one of the pressure side or suction side, with a connecting passage fluidly coupling the inlet to the outlet.

Abstract: A crank angle detection device for an engine capable of achieving downsizing and enhancing appearance of the engine is provided. A crank angle detection device for an engine that includes a pulsar ring including a plurality of detection portions and rotating coaxially with a crank shaft of the engine, and a sensor detecting a passage state of the detection portions. Here, the pulsar ring is fixed to a crank web of the crank shaft. A weight for adjusting inertia balance of the crank shaft is fixed to the crank web arranged close to an end of the crank shaft in an axial direction. The weight has a shape obtained by increasing thickness of a part of the pulsar ring.

Abstract: The invention relates to a method of determining the vertical profile of the wind speed upstream from a wind turbine (1), wherein wind speed measurements are performed by a LiDAR sensor (2), then the exponent ? of the power law is determined by an unscented Kalman filter and measurements, and the exponent ? is applied to the power law in order to determine the vertical wind speed profile.

Abstract: Provided is a wind turbine blade spar cap for a wind turbine blade for a wind turbine, the wind turbine blade including a down conductor, the wind turbine blade spar cap including at least one carbon element and at least one conductive layer, wherein the at least one carbon element and the at least one conductive layer are electrically connected, and at least one conductive profile to electrically connect the at least one conductive layer to the down conductor of the wind turbine blade, wherein the conductive profile is electrically connected to the at least one conductive layer and wherein the conductive profile is arranged at the wind turbine blade spar cap. Also provided is a wind turbine blade including a spar cap and a wind turbine including wind turbine blades.

Abstract: A method may include obtaining a normal set point of a solar panel and a wind velocity measurement corresponding to wind that affects the solar panel. The method may include determining an allowable range of tilt angles according to a first lookup table that describes a relationship between the wind velocity measurement and the allowable range of tilt angles. The method may include identifying whether the normal set point of the solar panel is outside of the allowable range of tilt angles, and responsive to identifying that the normal set point of the solar panel is outside of the allowable range of tilt angles, determining a temporary stow set point. The method may include rotating the solar panel to the temporary stow set point.

Abstract: A bearing arrangement for a wind turbine including a bearing housing and a drive shaft, whereby the drive shaft is arranged within the bearing housing in an axial direction along a longitudinal axis of the bearing housing, the bearing arrangement further comprising a downwind bearing and an upwind bearing as radial fluid bearings, whereby the downwind bearing and the upwind bearing are arranged between the bearing housing and the drive shaft is provided. The downwind bearing and/or the upwind bearing includes a lubricant flooded chamber, in which multiple radial bearing pads are arranged about the drive shaft, whereby the lubricant flooded chamber is sealed against the drive shaft, an internal space of the bearing housing and an outside of the bearing housing is also provided.

Abstract: A rotor blade for a wind turbine, to a wind turbine comprising a tower, a nacelle and a rotor, and also to a wind farm. The rotor blade comprises an inner blade section that extends from a rotor blade root in the longitudinal direction of the rotor blade, and a trailing edge segment, arranged on the inner blade section, for increasing the profile depth of the rotor blade along a section in the longitudinal direction of the rotor blade. The rotor blade has a pressure-side surface and a suction-side surface, which are each formed in certain regions by parts of the inner blade section and of the trailing edge segment. One or more air outlets and air inlets extending substantially in the longitudinal direction of the rotor blade are formed on both the pressure-side surface and the suction-side surface of the rotor blade, in the region of the trailing edge segment, said air outlets and air inlets being interconnected in a fluid-guiding manner.

Abstract: A sensor device for measuring flow-separation on an aerodynamic element, including a number of compliant elements with aerodynamic and/or structural properties designed to allow flow-induced vibrational motion in an air current and a sensor-element designed to measure vibrations of the number of compliant elements is provided. Further provided is an aerodynamic element, e.g. a wind turbine blade or an airfoil, with such sensor device, a method for controlling the angle of attack of an aerodynamic element, a controlling device and a wind turbine.

Abstract: Embodiments are directed to systems and methods for providing a control link for an aircraft in which the control link comprises an impact-resistant structure with a redundant load path. The control link has an inner structure that is sized to carry the anticipated load of the flight control system and to meet all safety factors. The control link also has an outer structure that is sacrificial and configured to absorb impact damage during operation, thereby protecting the inner structure. The outer structure is also designed to carry the anticipated load of the flight control system on its own, independent of the inner structure, and to meet all safety factors. If the outer structure fails, the inner structure allows for continued safe operation of the flight control system. The space or cavity between the inner and outer structures may be filled with a material, such as a closed-cell foam, to improve the impact resistance of the outer structure.

Abstract: Embodiments herein describe a method and associated controller for a wind turbine. The method comprises determining one or more characteristics of a sensor signal received from a mechanical sensor of the wind turbine; determining, based on the one or more characteristics of the sensor signal, an icing condition of the wind turbine; and controlling operation of one or more wind turbine systems based on the determined icing condition.

Abstract: Composite components and methods for forming composite components are provided. For example, a composite component of a gas turbine engine comprises a composite material, a plurality of piezoelectric fibers, and an anti-icing mechanism. The anti-icing mechanism is in operative communication with the piezoelectric fibers such that the anti-icing mechanism is activated by one or more electrical signals from the piezoelectric fibers. In exemplary embodiments, the composite component is a composite airfoil and the anti-icing mechanism is one or more heating elements. Methods for forming composite components may comprise forming piezoelectric plies comprising piezoelectric fibers embedded in a matrix material; forming reinforcing plies comprising reinforcing fibers embedded in the matrix material; laying up the piezoelectric and reinforcing plies to form a ply layup; and processing the ply layup to form the composite component.

Abstract: A rotor craft changes a torsional angle of a blade by driving an actuator. The rotor craft includes a plurality of torsion applying mechanisms that each twist a proximal end portion of a corresponding blade relative to a distal end portion of the corresponding blade about a center axis A of the blade. Each blade includes a spar having a proximal end portion connected to a hub and a skin in which the spar is inserted, such that a distal end portion of the skin and a distal end portion of the spar are connected to each other, and such that other portions of the skin than the distal end portion are rotatable relative to the spar about a center axis of the spar. The hub includes a hub body mounted to a main rotor shaft, and a hub arm that connects the spar to the hub body.

Abstract: Described is a system for monitoring deflection of turbine blades of a wind turbine comprising a tower. The system comprises a position detecting apparatus mounted to the wind turbine, the position detection apparatus comprising position detection components each detecting a presence or absence of a corresponding one of the segments of the turbine blades; and a deflection controller configured to receive the presence or absence detection and to use the presence or absence detection to determine a distance of each of the segments of the turbine blades relative to the tower, whereby the distance of each of the segments of the turbine blades relative to the tower is representative of the deflection of the turbine blades.

Abstract: A method of operating a marine vessel hybrid propulsion system having a propulsion shaft and a propeller, an internal combustion piston engine in force transmission connection with the propulsion shaft, and an electric motor-generator in force transmission connection with the propulsion shaft and/or with the piston engine. The internal combustion piston engine can be started by applying electric power from an on-board power source to the electric motor-generator and rotating the internal combustion piston engine by the electric motor-generator and rotational speed of the internal combustion piston engine is accelerated to a predetermined limit rotational speed without attempting to start the internal combustion piston engine, and only after the rotational speed of the internal combustion piston engine reaches the predetermined limit rotational speed, the internal combustion piston engine is started.

Abstract: Provided is a wind turbine blade for a wind turbine, the wind turbine blade including a root, a tip, a trailing edge, a leading edge and at least two beams including carbon fiber-reinforced plastic and being spaced apart from one another, wherein the at least two beams are arranged in the wind turbine blade in the longitudinal direction of the wind turbine blade at the trailing edge or within a distance of 25% of the width from the trailing edge, whereby the at least two beams are electrically connected to one another by at least one electrically conductive member and at least one of the at least two beams and/or at least one of the at least one electrically conductive member is configured to be connected to a down conductor of the wind turbine.

Abstract: The present invention relates to a method of identifying an electrical contact fault in a wind turbine blade electrical heating system, comprising inserting a predetermined enforced off cycle between or within a switching duty cycle, wherein the switching duty cycle controls the switching of one or more electrical contacts in the electrical heating system, measuring a current consumption during the predetermined enforced off cycle, determining if the measured current consumption exceeds a predetermined threshold, and wherein if the measured current consumption exceeds the predetermined threshold shutting down at least part of the electrical heating system. The present invention also relates to a wind turbine with one or more wind turbine blades that can identify an electrical contact fault.

Abstract: A method for protecting a wind turbine from extreme and fatigue loads associated with high wind speed events includes receiving, via a wind turbine condition estimator programmed in a turbine controller of the wind turbine, operating data indicative of current wind turbine operation. Further, the method includes determining, via the wind turbine condition estimator, a plurality of estimated wind turbine conditions at the wind turbine by solving a control algorithm having one or more equations using the operating data. The estimated wind turbine conditions include, at least, an estimated wind speed at the wind turbine and a loading proxy of the wind turbine. As such, the method includes implementing, via the turbine controller, a corrective action only when each of the estimated wind turbine conditions indicates that one or more loading conditions of the wind turbine exceeds a predetermined limit.

Abstract: Embodiments of the present disclosure include a retrofit auxiliary nacelle yaw position control system that enables advanced nacelle yaw position control of a wind turbine by comparing a desired nacelle yaw position signal with the actual nacelle yaw position and generating a virtual relative wind direction signal that is provided to the existing turbine control unit. This method and system enable implementation of wake steering, collective yaw optimization and dynamic yaw optimization of a collection of wind turbines referred to as a wind plant. Modification of the existing turbine control unit is not required, greatly simplifying the implementation process of advanced yaw control strategies on existing wind plants.

Abstract: Provided is a method for adjusting a pitch angle of a rotor blade connected to a rotor of a wind turbine, the method includes: pitching the rotor blade towards a target blade pitch angle, the manner of pitching depending on a load on a pitch bearing and/or an azimuthal position of the rotor.

Abstract: A wind turbine controller includes a thrust limiter for controlling the thrust of the blades of wind turbine using an estimate of the air density at the wind turbine. In one embodiment, the controller receives the blade flap load indicating the current load on one of the blades which varies linearly to the air density experienced by the wind turbine. In one embodiment, the controller determines the mean of a plurality of the blade flap load values measured during a predefined time period. Using a transfer function, the controller converts the mean of the blade flap loads to an estimate of the air density at the turbine. Generally, higher air density results in greater loads on the blades while lower air density results in lower loads on the blades.

Abstract: Embodiments of the present disclosure include a data processing and control augmentation system capable of identifying overloading of one or more wind turbine assemblies and providing information to a wind farm controller to reduce a power output of each overloaded turbine. The augmentation system thus reduces the power output of each overloaded turbine and, in turn, reduces loads applied to the wind turbine assembly, such as for a period of time until conditions favorably change. A described analysis of the present disclosure is able to utilize several incoming data streams from sensors so arranged to measure wind effects on blades to calculate and compare cyclic loads to threshold limits to o keep the loads within design limits. The control strategy reduces premature failure of components within the wind turbine assembly, and can be applied across an entire wind farm, even with only a subset of wind turbine assemblies being retrofitted.

Abstract: A fan device used with respect to a computing device. The fan device includes at least two fans that provide airflow for the computing device and a controller that adjusts the fans' speeds in an attempt to avoid harmonic vibrations of the at least two fans. The fan device may include at least one sensor, and the controller may adjust the fans' speeds based at least on information from the sensor(s) in the attempt to avoid the harmonic vibrations. The attempt to avoid the harmonic vibrations may also attempt to mitigate one or more of turbulence, pressure, over-heating, power consumption, or noise in, by, or around the computing device. Reversal of airflow may also be used. A fan bar that enables isolation of ground return noise may also be used. The controller may use sums of primes calculations, phase analysis, common divisor calculations, and the like. Also, associated methods.

Abstract: A method for wind turbine tower damping is disclosed, as well as an associated controller and wind turbine. The method comprises generating, using at least a first sensor signal, a first pitch reference signal for one or more rotor blades of a wind turbine during partial load operation. The method further comprises determining, using at least a second sensor signal, dynamic state information for a tower of the wind turbine. The method further comprises generating a second pitch reference signal by adapting the first pitch reference signal using the dynamic state information. The method further comprises selecting a maximum pitch reference signal from the second pitch reference signal and a saturation pitch reference signal. The method further comprises communicating the maximum pitch reference signal to control a pitch of the one or more rotor blades.

Abstract: A blade angle feedback ring assembly for an aircraft engine propeller having adjustable angle blades is provided. The feedback ring assembly comprises a feedback ring coupled to rotate with the propeller, the engine configured such that a first electrically-conductive path is defined between the propeller and the engine via the feedback ring, and an electric current conduction element provided between the propeller and the engine to define a second electrically-conductive path between the propeller and the engine in parallel to the first path, the second electrically-conductive path configured with a lower electrical resistance to conduction between the propeller and the engine than the first electrically-conductive path.

Abstract: Described herein are various systems and techniques for deterring wildlife from an area proximate a windmill. A flying wildlife emitter may be utilized for such techniques. The flying wildlife emitter may output soundwaves to deter wildlife, such as birds or bats, from entering an area around the windmill. The flying wildlife emitter may include a speaker for producing sounds as well as a controller and sensors for determining conditions around the windmill and for controlling the sound produced by the speaker.