1400 results about "Blade pitch" patented technology

A variable speed wind turbine employing a rotor connected to a multiplicity of synchronous generators with wound field or permanent magnet rotors. A passive rectifier and an inverter are used for power transfer back to the grid. A Turbine Control Unit (TCU) commands a required generator torque based on rotor speed and power output of the turbine inverters. Torque is controlled by regulating the DC current by control of the inverter. A main-shaft-damping filter is provided by measurement of the DC bus voltage. In high winds the turbine remains at a constant average output power through a constant torque command and a varying pitch command to a rotor pitch servo system. A set point is fixed at the inverter output such that output VAR load is minimized running the turbine at very nearly unity power factor. Dynamic VAR and power factor control is provided by a separate VAR apparatus.

A turbine control system for a variable speed electrical generator in a wind turbine mounted atop a support tower. The wind turbine converts wind energy into a driving torque applied to the generator. The control system includes a turbine support tower position sensor and may also include other tower acceleration and velocity sensors. A wind flow estimator uses the measured motion, generator rotation rate and blade pitch angle to predict wind flow over the swept area of the turbine's rotor, and the tower motion. The predicted wind flow and motion is used in the turbine control system to properly adjust its operating point, to tune the controller, to control the rotor rotation rate, and to damp tower oscillations.

A wind energy conversion system includes upper and lower wind turbines having counter-rotating blade assemblies supported for rotation about a vertical rotation axis, with each blade assembly carrying a rotor for rotation past a stator to produce an electrical output. The wind turbines are supported by a tower at an elevated position above the ground. Each wind turbine produces torque, and the wind energy conversion system provides for balancing the torques to avoid a net torque on the tower. Adjustment mechanisms are provided for adjusting blade pitch and for adjusting the size of an air gap between a stator and a rotor that comes into alignment with the stator as the rotor rotates therepast. The wind energy conversion system provides a hood for supplying intake air to a wind turbine and an exhaust plenum for exhausting air from the wind turbine, with the hood and the exhaust plenum being directionally positionable.

A turbine includes a turbine blade, a plurality of sensors, a wireless sensor module, a data aggregator, and a blade pitch control unit. The plurality of sensors are distributed in a plurality of locations on the turbine blade suitable for determining a moment of the turbine blade. The sensor module is configured to transmit data to the data aggregator to determine the moment. The data aggregator is configured to provide an output to the blade pitch control unit. The blade pitch control unit is configured to adjust pitch of the turbine blade based on the moment.

An aircraft including an airframe having a fuselage which extends longitudinally, and having fixed wings including a main wing, a horizontal tail wing and a vertical tail wing. A propeller-rotor torque transmission has a bevel gear which transmits the rotation of an input shaft simultaneously to a propeller shaft and to a rotor shaft. An engine gearbox supplies the above-mentioned input shaft with rotationalal motive power. The aircraft further includes a propeller collective pitch controller, a rotor collective pitch controller, an engine power controller which controls the output of the above-mentioned engine gearbox for the purpose of changing the rotational speed of the input shaft, and a flight control system having a directional (yaw) control system which controls the flight direction of the aircraft by controlling the positions of the above-mentioned control surfaces.

A variable speed wind turbine having a passive grid side rectifier using scalar power control and dependent pitch control is disclosed. The variable speed turbine may include an electrical generator to provide power for a power grid and a power conversion system coupled to the electrical generator. The power conversion system may include at least one passive grid side rectifier. The power conversion system may provide power to the electrical generator using the passive grid side rectifier. The variable speed wind turbine may also use scalar power control to provide more precise control of electrical quantities on the power grid. The variable speed wind turbine may further use dependent pitch control to improve responsiveness of the wind turbine.

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

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.

The axial fan assembly according to some embodiments of the present invention has a shroud, a motor coupled to the shroud, and a fan coupled to the motor. By employing selected vane-to-blade ratios, blade twist angles, blade pitch angles, blade-to-shroud axial gaps, shroud solidities, vane swept angles, and vane inlet and outlet angles of specified amounts or falling within specified ranges, desirable fan performance is achieved. Any one or more of these parameters can be utilized alone or in combination with other parameters as desired.

A rotor for use on an aircraft has a plurality (N) of rotor blades mounted on a plurality (N) of concentric masts. Each of the rotor blades has a rounded leading edge and a tapered trailing edge. The plurality (N) of concentric masts each operably mount one of the plurality of rotor blades at N different elevations. A locking element selectively locks or unlocks the concentric masts together in a plane of rotation, enabling the angle between any two rotor blades to be variable from 0-360 degrees during flight. A feathering hinge is operably attached to each blade for changing the pitch of each blade with respect to the plane of rotation as controlled by a pitch control mechanism.

A wind energy conversion system includes upper and lower wind turbines having counter-rotating blade assemblies supported for rotation about a vertical rotation axis, with each blade assembly carrying a rotor for rotation past a stator to produce an electrical output. The wind turbines are supported by a tower at an elevated position above the ground. Each wind turbine produces torque, and the wind energy conversion system provides for balancing the torques to avoid a net torque on the tower. Adjustment mechanisms are provided for adjusting blade pitch and for adjusting the size of an air gap between a stator and a rotor that comes into alignment with the stator as the rotor rotates therepast. The wind energy conversion system provides a hood for supplying intake air to a wind turbine and an exhaust plenum for exhausting air from the wind turbine, with the hood and the exhaust plenum being directionally positionable.

A wind power generation system wherein procedure for controlling the blade pitch is changed in accordance with the rate of decrease in the amplitude of the grid voltage, and when over current occurs in the grid-side power converter, the grid-side power converter is brought into the gate-blocked condition whereas the generator-side power converter continues its operation.

A wind turbine system is provided with a wind turbine rotor, a pitch control mechanism, and an emergency power supply mechanism. The wind turbine rotor includes a blade having a variable pitch angle. The pitch control mechanism drives the blade to control the pitch angle. The emergency power supply mechanism generates electric power from rotation of the wind turbine rotor and feeds the electric power to the pitch control mechanism, in response to occurrence of an accidental drop of a system voltage of a power grid.

A method and mechanism for adjusting / controlling the pitch of at least one blade of a wind turbine relative to a wind direction parallel to a longitudinal main shaft of the wind turbine use a mechanism with a motor for rotating drive wheels in the angle gear around a longitudinal blade shaft via drive wheels of an angle gear. The method and mechanism can stop the complete turning of a main shaft of a wind turbine having a motor to rotate a drive pinion in an angle gear via a drive wheel, the angle gear being meant to pitch at least one blade around a longitudinal axis.

A coaxial helicopter, comprising a first rotor carried by a first shaft and a second rotor carried by a second shaft; wherein one of the first and second rotors has cyclic pitch control and the other rotor does not have cyclic pitch control, at least pitch and roll control being implemented by cyclic blade pitch control of only one rotor of the coaxial rotor set. Provisions for yaw control can include differential collective control of the first and second rotors, providing yaw paddles and / or a tail rotor, ducted fan, or an air jet configured for yawing the coaxial helicopter.

A turbine control system for a variable speed electrical generator in a wind turbine mounted atop a support tower. The wind turbine converts wind energy into a driving torque applied to the generator. The control system includes a turbine support tower position sensor and may also include other tower acceleration and velocity sensors. A wind flow estimator uses the measured motion, generator rotation rate and blade pitch angle to predict wind flow over the swept area of the turbine's rotor, and the tower motion. The predicted wind flow and motion is used in the turbine control system to properly adjust its operating point, to tune the controller, to control the rotor rotation rate, and to damp tower oscillations.

A control system for a coaxial rotorcraft comprises a coaxial rotor set, further comprising an upper rotor actuated by a first drive shaft and a lower rotor actuated by a second drive shaft, the lower rotor having a direction of rotation counter to a direction of rotation of the upper rotor. A collective blade pitch control is configured to: collectively control pitch of only one of the upper rotor and the lower rotor and not another of the upper rotor and the lower rotor; and create an unbalanced torque force which acts on the rotorcraft and which enables a yaw attitude control input through said collective blade pitch control.

A wind turbine generator, an active damping method thereof, and a windmill tower in which vibrations of the wind turbine generator itself or the windmill tower can be reduced at low cost are provided. The acceleration due to vibrations of a nacelle (13) is detected with an accelerometer (17) attached to the nacelle (13). In an active damping unit (20), a pitch angle of windmill blades (12) for generating a thrust on the windmill blades (12) so as to cancel out the vibrations of the nacelle (13) is calculated on the basis of the acceleration, and the pitch angle is output as a blade-pitch-angle command δθ* for damping. On the other hand, in a pitch-angle control unit (30), a pitch angle of the windmill blades (12) for controlling the output to be a predetermined value is calculated, and the pitch angle is output as a blade-pitch-angle command θ* for output control. The blade-pitch-angle command δθ* for damping is combined with the blade-pitch-angle command θ* for output control using a subtracter (40). The pitch angle of the windmill blades is controlled on the basis of the resulting blade-pitch-angle command after combining.

A wind turbine generator, an active damping method thereof, and a windmill tower in which vibrations of the wind turbine generator itself or the windmill tower can be reduced at low cost are provided. The acceleration due to vibrations of a nacelle (13) is detected with an accelerometer (17) attached to the nacelle (13). In an active damping unit (20), a pitch angle of windmill blades (12) for generating a thrust on the windmill blades (12) so as to cancel out the vibrations of the nacelle (13) is calculated on the basis of the acceleration, and the pitch angle is output as a blade-pitch-angle command δθ* for damping. On the other hand, in a pitch-angle control unit (30), a pitch angle of the windmill blades (12) for controlling the output to be a predetermined value is calculated, and the pitch angle is output as a blade-pitch-angle command θ* for output control. The blade-pitch-angle command δθ* for damping is combined with the blade-pitch-angle command θ* for output control using a subtracter (40). The pitch angle of the windmill blades is controlled on the basis of the resulting blade-pitch-angle command after combining.

The present invention relates to a device for locking the pitch of the blades of a main rotor of a rotary-wing aircraft in which each blade is firstly rotated about an axis of rotation of the rotor by a rotor mast and is secondly constrained to pivot about a longitudinal pitch axis of the blade together with a pitch lever which is controlled by a pitch link connected to a rotary plate rotating with the rotor mast and belonging to a cyclic swash plate mechanism in which the rotary plate is rotatably mounted on a non-rotary plate capable of sliding axially along said rotor mast and of tilting in any direction relative to the rotor mast under the drive of at least three servo-controls each comprising a body fixed on a support secured to the aircraft and a rod having a free end secured to the non-rotary plate. The device includes immobilization means for holding the rod of each of the servo-controls relative to the corresponding body so as to lock the blades in a predetermined pitch position.

A vertical takeoff and landing aircraft having a fuselage with, preferably, three wings and six synchronously tilt-able propulsion units, each one mounted above, below, or on each half of the aforementioned three wings. The propulsion units are oriented vertically for vertical flight and horizontally for forward flight. Each propulsion unit comprises a propeller having a plurality of blades, where the pitch angle associated with the distal end of each blade and the proximal end of each blade are independently adjustable. As such, each of the propellers can be adjusted to exhibit a first blade pitch angle distribution optimized for vertical flight and a second blade pitch angle distribution optimized for forward flight.

Disclosed are a model prediction control method and a model prediction control system for all working conditions of a wind generating set. The system comprises an MPC (model prediction control) device, a feedback information measurer, a wind wheel, a driving chain, a tower, a generating unit, a variable propeller driver and a converter. The feedback information measurer is used for detecting status variables of the wind wheel, the driving chain, the tower and the generating unit and transmitting detecting results to the MPC device, the MPC device is used for computing targets of the blade pitch angle and the generator torque, and the variable propeller driver and the converter are used for adjusting the blade pitch angle and the wind generator torque. The method is used for computing control increment by means of a variable propeller control prediction model and a torque control prediction model, takes the status variables including driving chain torsional displacement, driving chain torsional speed, blade plane external first-order flap displacement, blade plane external first-order flap speed, tower front-back first-order swing displacement, tower front-back first-order swing speed, mechanical loads of the unit and the like, and two prediction models can be automatically switched in different working conditions, so that the wind generating set can be operated in all working conditions.

A method for calculating a high-altitude power curve for a wind turbine is provided, the method including the steps of determining a cp-λ curve for a predetermined blade pitch angle of said wind turbine; calculating a first power curve without power limit based on the cp-λ curve; and calculating the high-altitude power curve with power limit from said first power curve, thereby using a site air density.

This document discusses, among other things, a wind turbine blade pitch system for moving the blades to control their pitch in the event of a power failure. The system includes at least one backup that has a non-electrical component that can pitch the blades in the event that the power failure adversely affects the electrical blade pitch actuator system. Embodiments include pitch systems that have a plurality of pitch driving systems including, but not limited to electrical systems, hybrid electrical / mechanical systems and non-electrical systems. The non-electrical systems include mechanical, pneumatic or hydraulic systems.

A wind turbine system is provided with a wind turbine rotor, a pitch control mechanism, and an emergency power supply mechanism. The wind turbine rotor includes a blade having a variable pitch angle. The pitch control mechanism drives the blade to control the pitch angle. The emergency power supply mechanism generates electric power from rotation of the wind turbine rotor and feeds the electric power to the pitch control mechanism, in response to occurrence of an accidental drop of a system voltage of a power grid.

An aircraft is equipped with hingeless rotors on tilting nacelles, and the tilt angles of the nacelles are controlled using either or both of an actuator and a mast moment generated by a hingeless rotor. An aircraft with two or more rotors on tilting nacelles can achieve control of yaw orientation by differential tilt of its nacelles or masts. Hingeless rotors can be manipulated to control a tilt angle of a mast by changing the rotor blade pitch to produce a mast moment. The rotor and nacelle tilt of a tiltrotor rotorcraft can be controlled and effected in order to manipulate the yaw orientation and flight mode of a rotorcraft such as a tiltrotor. The use of mast moment to control nacelle tilt angle can reduce tilt actuator loads and allows for the control of nacelle tilt even in the event of an actuator failure.

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.

A hydraulic turbine power generator mounted on a single shaft wherein the hydraulic turbine means includes a plurality of reaction type turbine stages arranged to be in combination, rotatably responsive to the hydraulic fluid coupled to the turbines. One of the turbine stages having axial turbine runner means mounted to the single shaft and having a plurality of adjustable blades for permitting the pitch of the blades to be adjusted for controlling the effective operative fluid head to cause the shaft to rotate at a preselected speed and including means for adjusting the pitch of the adjustable blades. The turbine stages can be a Francis type turbine and a Kaplan type turbine. The hydraulic turbine power generator can be oriented in an upward direction to cause the fluid flow to travel upwardly through the turbine stages and function as a two phase turbine expander resulting in the separation of the liquid phase from the gas / vapor stage.