Abstract: The invention relates to a method for controlling a rotary wing aircraft with at least one main rotor, comprising a rotor head and rotor blades (12), arranged such that each rotor blade (12) is supported to be able to pivot or twist around the lengthwise axis of its blade on the rotor head and has at least one control flap (14) that can be deflected. According to the invention, the rotary wing aircraft is controlled solely by changing the respective blade pitch angle (X) by means of changing the flap control angle (Y) of the assigned control flaps (14) by the resulting blade pitch angle (X3) being set by applying the resulting flap angle (Y4) to the control flap (14), and the flap angle (Y4) being computed using an algorithm, the input quantities comprising the flap control angle (Y1) depending on the pilot primary control and the flap correction angle (Y2) depending on the secondary control.

Abstract: A wind turbine electrical generating device is described where the blades that comprise the airfoil are retractable during operation. This feature allows for a number of improvements over the current state of the art including damage protection and the ability to remain operational during high wind conditions. Further described is a computer feedback loop that controls the degree of retraction. In addition, lightweight airfoil turbine blades are described that are assembled from discrete segments.

Abstract: A wind turbine may be controlled in a variety of manners to optimize operating parameters. In one arrangement, for example, the length or the pitch of a wind turbine rotor blade may be adjusted to avoid harmonic resonance frequencies. In another example, the length of a rotor blade may be modified to reduce noise or to optimize profits or both. The controls may be based on data from various types of sensors including accelerometers, sound meters, strain gauges and the like. Actuation of extendable rotor blades can rotate wind turbine rotors without wind or generator pulsing affording multiple advantages. A battery test control may also be used to determine the operational readiness of a battery useful for a variety of purposes in a turbine.

Abstract: Systems and methods use cyclical propellers with dynamic blade angle control to extract power from waves. A control system for such implementations can adapt pitching schedules for the blades of the cyclical propellers for efficient energy extraction and/or to control reactive forces. The cyclical propellers may be installed on the floor of a body of water or other liquid, on a submarine, or on a surface float, and blades may extend vertically or horizontally depending on the character of the waves. Several cyclical propellers can be combined into a single unit operated to minimize net reactive force or torque, to propel the unit horizontally or vertically, and/or to stabilize the unit. Such units can be installed with minimal or no moorings.

Abstract: A system and method of providing noise control for a wind turbine are provided. The system includes at least one blade operably mounted on a wind turbine, and one or more sensors for receiving one or more signals relating to an operating characteristic of the wind turbine. A controller is configured for evaluating the signals to determine if they are outside a predetermined range. The system is configured to adjust operating characteristics and/or generate alarms if the signals are outside a predetermined range. The method includes the steps of receiving one or more signals from one or more sensors, determining if the signals are outside a predetermined range, and adjusting an operating parameter of the wind turbine or generating an alarm in response to the signals received from the sensors. The operating parameter can be adjusted to alter the amount of noise generated by the wind turbine.

Abstract: An active flow control (AFC) system for use with a wind turbine is provided. The wind turbine includes at least one rotor blade having at least one manifold extending at least partially therethrough and at least one aperture defined through a surface of the at least one rotor blade. The at least one aperture is in flow communication with the at least one manifold. The AFC system includes an air intake duct configured to draw ambient air into the wind turbine, a self-cleaning air filter coupled in flow communication with the air intake duct and configured to filter the ambient air, and an AFC distribution system configured to eject the filtered air through the at least one aperture.

Abstract: A method and an apparatus for monitoring an acoustic emission of a wind turbine that includes a rotor blade. The apparatus includes at least one sensor operatively coupled to the wind turbine. The sensor is configured to detect an atmospheric condition. A control system is communicatively coupled to the sensor, and configured to control operation of the wind turbine to adjust the acoustic emission of the wind turbine based on the atmospheric condition.

Abstract: A method of operating a wind turbine is provided. The wind turbine has at least one rotor blade and an active flow control (AFC) system. The at least one rotor blade has at least one aperture defined through a surface thereof, and the AFC system is configured to modify aerodynamic properties of the at least one rotor blade by ejecting gas through the at least one aperture. The method includes operating the wind turbine in a first mode, determining an environmental condition surrounding the wind turbine indicative of fouling of the AFC system, and operating the wind turbine in a second mode different than the first mode based on the environmental condition. The second mode facilitates reducing fouling of the AFC system.

Abstract: A monitoring system for at least one wind turbine includes at least one sensor disposed at the at least one wind turbine to detect wind friction at the at least one wind turbine. At least one controller is connected to the at least one wind turbine, and a monitor server is connected to the controller to change an operational status of the at least one wind turbine based on wind friction data received from the at least one sensor. A method of operation of at least one wind turbine includes continuously measuring data relative to wind friction at the at least one wind turbine via at least one sensor located thereat. The data is continuously compared to a predetermined wind friction threshold. A trend in the comparisons is evaluated, and the operational status of the wind turbine is changed via a monitor server based on a result of the comparison.

Abstract: In order to prevent minor deviations from expected operation in a yawing system before they lead to larger deviations, there is in accordance with a method aspect of the invention disclosed monitoring and determining deviation from an expected operation in a yawing system of a wind turbine. The method includes inputting a rotation angle input to at least one of a plurality of yaw motors, sensing an angular output of at least one of the plurality of yaw motors, receiving the rotation angle input to the at least one of the plurality of yaw motors in a signal processor, receiving the angular output of the at least one of the plurality of yaw motors, comparing at least two of the received signals, and/or comparing a mathematical relation of two of the received signals with a reference, and hereby determining whether there is any deviation from the expected operation.

Abstract: A method performed by a control system for operating a wind turbine includes operating a flow control system of the wind turbine in a first mode, and operating the flow control system in a second mode different than the first mode to facilitate removing debris from the flow control system. The second mode includes varying at least one of a velocity, a flow rate, and a direction of a fluid flow of the flow control system.

Abstract: A method and system for providing noise control for a wind turbine system are disclosed. The method can include providing a wind turbine system comprising at least one blade operably mounted on the wind turbine and a controller, determining an external condition with at least one sensor, receiving a noise control signal related to the external condition, and adjusting an operating parameter in response to receiving the noise control signal related to the external condition.

Abstract: A wind turbine has a horizontal axis of rotation and features a hub beam and two turbine blades attached to opposing ends of the hub beam in a spaced-apart relation. The blades have a first position in which the blades are radially arrayed about the hub beam. The blades have a second position in which the blades are folded and moored to the tower. A control system communicates with weather sensors and determines whether to move the blades between the first and second positions.

Abstract: A method for controlling noise generated from a wind turbine. The method including providing a blade attached to a hub having a rotor shaft, and a generator in communication with the rotor shaft. The at least one blade includes an adjustable pitch angle. The method further includes providing a wind turbine acoustical profile and a wind turbine power profile. The wind turbine acoustical profile and the wind turbine power profile are compared to determine a noise reduced operational condition. The wind turbine is controlled to provide a rotor speed and the pitch angle of the blade corresponding to the noise reduced operational condition.

Abstract: A method for controlling operation of a wind turbine is described. The wind turbine includes a rotor having a plurality of rotor blades and an upwind wind condition measurement device. The method includes measuring a wind condition upwind from the rotor using the upwind wind condition measurement device and providing the measured wind condition to a processor. The method also includes determining a control algorithm parameter, based at least partially on the measured wind condition, that controls at least one of a wind turbine response bandwidth, a wind turbine response speed, and a wind turbine control error range. The method also includes determining a wind turbine operating command based at least partially on the control algorithm parameter and applying the wind turbine operating command to operation of the wind turbine.

Abstract: A engine such as a gas turbine engine has a bladed rotor 24 having variable pitch blades 8. In normal operation, the pitch angle of the blades 8 is controlled by a primary pitch control system. A back-up system is provided for controlling the blades 8, for example to displace them to a feathered condition, in the event of failure of the primary pitch control system. The back-up system comprises a pump 32 mounted on the rotor 24, and driven by relative rotation between the rotor 24 and a contra-rotating rotor 23. In response to a failure signal on a conduit 48, the pump delivers hydraulic fluid under pressure to a secondary actuator 30, which acts on the blade 8.

Abstract: A system for measuring clearance between a first object and a second object is provided. The system includes a sensor configuration to generate a first signal representative of a first sensed parameter and a second signal representative of a second sensed parameter. The system also includes a clearance measurement unit configured to process the first and second signals based upon a ratiometric technique to calculate clearance between the first and second objects.

Abstract: A wind turbine including a torque distribution device for distributing torque between two different shafts. Also a system for detecting the presence of snow/ice on a wind turbine using ultrasound sensors and a system for de-icing wind turbines in which when the removal of snow/ice is detected, the heaters are switched off. Also a wind turbine with a lightning sensor and a processing unit which can shut down sub-systems or the whole system in response to data from the lightning sensor. Also a wind turbine with an automated lubrication refill system for replenishing the lubricant in one or more components of the turbine. Also a wind farm comprising a plurality of wind turbines in which at least one wind turbine is communicatively coupled to at least one other wind turbine.

Abstract: A wind system (1) is described for converting energy comprising at least one kite (2) that can be driven from ground immersed in at least one wind current (W) and at least one module (5) adapted to translate on at least one rail (6; 7) placed next to the ground, such module (5) being connected through at least one rope (4) to the kite (2), in order to drag the module (5) on the rail (6; 7) and to perform a conversion of wind energy into electric energy through at least one electric energy generating system cooperating with module (5) and rail (6; I) 1 such rope (4) being adapted both to transmit mechanical energy from and to the kite (2) and to control the flight trajectory of the kite (2).

Abstract: A method for wind turbine tower load control includes controlling the pitch of the rotor blades in a conventional manner by a collective command component. An estimator estimates the tower resonant acceleration and the thrice-per-revolution blade imbalance acceleration. Combining logic, connected to the estimated resonant acceleration and to the estimated thrice-per-revolution (3P) acceleration provides a combined pitch modulation to damp the tower resonant motion and the thrice-per-revolution motion using collective modulation. The pitch modulation is combined with the collective command component to drive the pitch actuators.

Abstract: A system for environmental control includes a hybrid wind and solar energy collection subsystem; a temperature control subsystem having a thermo-mechanical engine; an electrical generating subsystem; a sensor for detecting an environmental condition; and a controller for receiving information representing an environmental condition from the sensor. The controller is programmed to detect a change in an environmental condition, and in response to the change, to selectively connect the hybrid wind and solar energy collection subsystem to one of the temperature control subsystem and the electrical generating subsystem and to selectively disconnect the hybrid wind and solar energy collection subsystem from the other of the temperature control subsystem and the electrical generating subsystem.

Abstract: Active Circulation Control (ACC) of aerodynamic structures, such as a turbine blade, uses unsteady or oscillatory flow from either synthetic jets or pulsed jets to modify a velocity profile of the blade. The blade includes an opening disposed in a surface of the blade at a location proximate to a trailing edge, a leading edge, or both the trailing edge and the leading edge of the blade. An active flow control device in fluid communication with the opening produces a wall-jet of pulsed fluid that flows over the trailing edge, the leading edge, or both the trailing and leading edges of the blade and modify the velocity profile of the blade.

Abstract: A propeller (1) comprising a hub, and a plurality of fins (3) extending radially outwards from the hub, wherein each fin is moveably connected to the hub such that, during rotation of the propeller, the dihedral of each fin can be altered and controlled over a working range by movement of that fin about one or more axes of rotation (BB).

Abstract: A method for operating a wind turbine having a rotor with a number of wind turbine blades, wherein the rotor's axis of rotation is tilted in relation to the direction of the incoming wind, includes the steps of determining the azimuth angle (A) of the blades and adjusting the pitch angle of the blades in accordance with the azimuth angle (A) to ensure a substantially constant angle of attack (AoA) during at least a full rotation of the rotor. A wind turbine and use of the method are also contemplated.

Abstract: A wind turbine includes a first vibration sensor for producing a first vibration signal; a second vibration sensor, displaced from the first vibration sensor, for producing a second vibration signal; and a processor for comparing the first vibration signal to the second vibration signal and controlling the wind turbine in response to the comparison.

Abstract: A method for stopping a pitch controlled wind turbine comprising a rotor with at least one blade (11), a mechanical brake (31) on the high speed shaft, a pitch system ((21, 23, 25) for adjusting the blade pitch angle, that includes: a) a first stage using the pitch system (21, 23, 25) for slowing down the rotor; b) a second stage using both the pitch system (21, 23, 25) and the mechanical brake (31) for stopping the rotor. The second stage begins when one of the following conditions takes place: the high speed shaft rotational speed is under a predefined value So; a predefined time delay To with respect to the beginning of the first stage is reached; a predefined high speed shaft torque level TLo is reached.

Abstract: A method of controlling blade pitch angle, comprising the steps of: comparing demanded and measured blade pitch angle and calculating any difference therebetween, in a primary electrical control system, where there is a difference, applying torque to a blade pitch regulator to reduce the magnitude of the difference to zero, and in a secondary electrical control system, where the difference is greater than a pre-determined threshold, applying torque to a blade pitch regulator to reduce the magnitude of the difference to the threshold. Also an electrical system of blade pitch angle control for a set of blades comprising: primary and secondary electrical control systems, means for comparing demanded and measured blade pitch angle and calculating any difference therebetween, a look-up function having the difference as its input and outputting a required torque, and a torque regulator to apply the required torque to the set of blades.

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

Abstract: The present invention provides an improvement for a wind turbine (20) having at least one blade (21) mounted on a hub (22) for controlled rotation about a blade axis (yb-yb) to vary the pitch of the blade relative to an airstream. The hub is mounted on a nacelle (23) for rotation about a hub axis (xh-xh). The wind turbine includes a main pitch control system for selectively controlling the pitch of the blade, and/or a safety pitch control system for overriding the main blade pitch control system and for causing the blade to move toward a feathered position in the event of an overspeed or fault condition.

Abstract: A method for cleaning the blades of a wind turbine using precipitation. The method includes determining the presence or absence of precipitation. In response to the determination of the presence of precipitation, adjusting the rotor speed to increase the speed of the blades and/or adjusting the variable pitch drive to increase the pitch of the blades. The combination of the increased blade speed and/or the increase blade pitch and the presence of precipitation facilitate the removal of debris from the blades by the precipitation.

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

Abstract: A propeller comprising a hub (101) and a plurality of fins (3) extending radially outwards from the hub, wherein each fin is moveably connected to the hub such that, during rotation of the propeller, either the dihedral, the rake or both the dihedral and the rake of the fin(s) can be altered and controlled over a working range by movement of the fin(s) about one or more axes of rotation; and one or more actuators for controlling the dihedral or rake of the fins independently of the pitch of the fins.

Abstract: A method for doing an optimization of the performance envelope initially authorized for an existing rotorcraft engine (M) to enable the engine (M), to be used in an optimized performance envelope that is different from the performance envelope initially authorized for the engine, is remarquable in that this optimization is compensated by modifying the total service life of the engine (M).

Abstract: An overhead fan system of a building comprises a ceiling fan underneath a nearby fire sprinkler head. The ceiling fan has particularly low fan solidity to minimize the fan obstructing the spray of water from the sprinkler head. To further reduce the obstruction, some example fans include fan blades that automatically retract in the event of a fire.

Abstract: Wind turbine comprising a rotor, a nacelle frame (13) housing with electrical generation means coupled to the rotor hub (11), braking means and control means of the drive train rotational position, the nacelle frame (13) and the rotor hub (11) having an arrangement for preventing the rotor hub (11) rotation when certain maintenance or assembly activities should be carried out, said arrangement including at least one sliding pin (21) in the nacelle (13), first actuating means (31) for pushing/pulling it axially into/from at least one corresponding hole (23) in the rotor hub (11) and means for allowing vertical and lateral adjustment displacements of said sliding pin (21) so that it can remain concentrically aligned with said hole (23) when it is inserted into it.

Abstract: A method for condition monitoring a rotor of a wind energy plant includes the steps of measuring activity signals of the blades in the rotor and establishing one or more differential values between the activity signals of different blades. The one or more differential values are used for monitoring the condition of the rotor in the wind energy plant. A wind energy plant, a cluster of wind energy plants and use hereof is also contemplated.

Abstract: A wind turbine or rotor load control compensates for moment imbalance in a wind turbine that includes a rotor having at least two variable pitch blades. The apparatus includes a conventional pitch command logic developing a nominal rotor blade pitch command signal and a moment sensor. The moment sensor can be one or more of a nacelle overturning moment sensor, and a turning moment sensor. An output of this is used as a moment signal. Conversion logic is connected to the moment signal with an output of the conversion logic being calculated individual pitch modulation commands for each of the blades. A combining logic is connected to receive the calculated individual blade pitch modulation commands and to receive a nominal pitch command. An output of the combining logic is individual combined blade pitch commands for each of the blades.

Abstract: A wind turbine is presented where the operation lifetime of the main bearing is extended by relieving the main bearing by reducing the mean bending moment on the bearing by means of individual pitch control of the blades of the rotor so as to create an aerodynamic mean tilt moment on the rotor by means of aerodynamic forces on the blades, the tilt moment at least partly counteracting the bending moment caused by the overhang load forces on the main bearing from the gravitational pull on the rotor mass.

Abstract: A system for driving a wind turbine blade (46) into a feathered position during an emergency stopping process of a wind turbine rotor. The system comprises a hydraulic actuator (3) functionally connected to the blade (46) for changing the pitch of the blade (46) during movement of the hydraulic actuator (3) and an emergency accumulator (8) connected to the hydraulic actuator (3) for driving the hydraulic actuator (3) with fluid from the emergency accumulator (8). The emergency accumulator (8) comprises a resilient member for accumulating the fluid in the emergency accumulator (8) under resilient pressure or a weight member (74) comprising a weight member upon the fluid in the emergency accumulator. The resilient member (14) or weight member (74) is configured for driving the fluid out of the emergency accumulator due to the expansion or retraction of the resilient member.

Abstract: The present invention provides a wind and wave power generation system including a platform (12) and a wind turbine (16) rotatably mounted on a tower (32) and provided with an actuator (34) for changing the yaw angle of the turbine blade (38) relative to said tower (32). The system further includes a sensor (118) for detecting at least yaw motion of the platform and a controller (56) for causing actuation of the actuator (34) to cause movement of the rotor so as to at least partially correct detected yaw motion.

Abstract: A dual, counter-rotating, coaxial rotor system provides individual control of an upper rotor system and a lower rotor system. The lower rotor control system and the upper rotor control system provide six controls or “knobs” to minimize or theoretically eliminate airframe vibration. In a dual, counter-rotating, coaxial rotor system, application of a HHC system to the two rotor systems individually but located on the common axis, will yield essentially complete vibration reduction because the 6 controls will suppress the 6 loads.

Abstract: A method an apparatus of automatically controlling a wind turbine re provided. of: A time-series of measurement values of the aerodynamic flow property of the wind turbine rotor blade is determined; a predictive wind field model representing a structure of a wind field acting on the wind turbine rotor blade is generated based on the time-series of measurement values, and a control value is generated based on the wind-field model.

Abstract: A method for damping edgewise oscillations in one or more blades of a wind turbine includes the steps of detecting if one or more of the blades oscillates edgewise during operation of the wind turbine, and substantially cyclically generating a pitch angle difference between at least two of the blades. Further provided is an active stall controlled wind turbine and use hereof.

Abstract: The invention concerns a method for reducing mechanical oscillation in a wind power plant which comprises a plurality of rotor blades, a wind turbine drive train and a generator, wherein the rotor blades are rotatably connected to the generator by the wind turbine drive train. The method comprises the steps: mathematically modeling the dynamical response and/or transfer function of a group of rotatable parts of the wind power plant, the group of rotatable parts comprising at least the wind turbine drive train, and determining dynamical response and/or transfer function of the group; in operation of the wind power plant, determining a first parameter characteristic of the mechanical oscillation at a first location, controlling the operation of at least one rotatable part in response to the dynamical response and/or transfer function of the group and at least the first parameter. In effect, resonance induced mechanical wear is reduced which leads to an increased life time of the wind power plant.

Abstract: A control system for mitigating the effects of a wind turbine on a radar system is disclosed. The control system includes a sensor configured to detect an operating condition of the radar system; a processor configured to receive an operating condition of the wind turbine and determine a rotation modification sequence based on the operating condition of the radar system and the operating condition of the wind turbine; and a controller configured to apply the rotation modification sequence to the wind turbine. A method of mitigating the effects of a wind turbine on a radar system is also disclosed.

Abstract: A compact variable pitch fan has a hydraulic pitch change mechanism. A pitch change piston is constrained to follow reciprocating motion under hydraulic control within a peripheral hub from which fan blades extend outward. An additional feature is the use of separated guiding and seal surfaces. A still further feature is the use of a pitch sensor, particularly on the hydraulic line leading to the variable pitch fan.

Abstract: The invention relates to a wind turbine comprising a rotor including one or more pitchable blades, and detection means for detecting edgewise oscillations in one or more of said blades. The wind turbine is characterized in that the wind turbine comprises control means for changing the pitch angle of one or more of the blades if the detection means detects edgewise oscillations in one or more of the blades, hereby damping or eliminating the edgewise oscillations. The invention further relates to a method for damping edgewise oscillations in one or more blades of a wind turbine and use hereof.

Abstract: The present invention provides a wind power generation device capable of reducing collision of a flying object against a blade or bird strike. The wind power generation device includes a tower set up on the ground, a nacelle fixed to the tower, a plurality of blades rotatably fixed to the nacelle via a hub, an obstacle search device capable of detecting a flying object existing in front, on the windward side, and a blade angle controller to control the change in angle of the blade including a rotation stop position. The obstacle search device searches for the flying object continuously, and when the flying object is determined to be approaching based on the continuous searching, the blade angle controller controls to change the blades to the rotation stop position.

Abstract: A rotor system includes a multiple of rotor blade yokes mounted to a rotor hub. A lead/lag damper is mounted to each of the rotor blade yokes and to a damper hub. An actuator system is operable to shift a damper hub axis of rotation relative the rotor axis of rotation to minimize 1P damper motions. A method of minimizing 1P damper motions within a rotor system includes shifting the damper hub axis of rotation relative the rotor axis of rotation to oscillate an inner connector of each lead/lag damper in phase with a 1P blade motion to minimize the 1P motion of the damper.

Abstract: A low-head impulse jet water turbine for electric power generation at irrigation canal drop structures, navigation dam spillways or other low head watercourses achieves renewable electric power generation at competitive cost. Kinetic energy of a low-pressure jet is employed in a way that enables numerous locations to generate electricity conveniently near points of use, from a renewable source at minimum cost. The equipment can be pre-assembled for minimum installation cost at sites with no existing impoundment and can be automatically raised clear of flood levels with built-in lifting equipment. Existing multi-span bridges offer convenient access for installation and maintenance. The system for raising the equipment also provides clear passage for fish migration.