A wind generator system with a plurality of lightweight, surface area adjustable airfoil/sail blades. Each blade is triangular or wedge shape with a narrow inner edge and a wide outer edge. Each blade includes an inner frame connected to a rigid mast that extends radially from a hub assembly. Each blade includes a curved outer skin layer that extends over the inner frame and configured into air foil shape with a large curved leading edge and a thin trailing edge. The outer skin layer is secured along its leading edge and removeably attached along its trailing edge to the inner frame. Advertising is printed on the outer skin of at least one blade that is visible. Coupled to the outer skin layer is a first linear actuator that when activated, causes the outer skin layer to fold or unfold thereby changing the blade's surface area. The internal frame may include a second linear actuator and a telescopic mast over which the blade slides to increase or decrease the sweep area of the blades. Wind or electrical sensors are coupled to the mast and the retractable cable to automatically control the sweep area and the surface areas.

Disclosed is an energy converting apparatus for converting mechanical energy obtained by a fluid flow into electric energy. The energy converting apparatus comprises: a blade; a measuring device for measuring reaction of the blade when the fluid flow exerts an external force on the blade, and generating a measurement value corresponding to a measurement result; a memory for storing control values; a controller for reading a first control value among the control values from the memory in response to the measurement value output from the measuring device, and generating a control signal by using the first control value; and an actuator for changing a three-dimensional shape of the blade in response to the control signal output from the controller.

A wind turbine is provided. The turbine includes a support having an axis of rotation, a generator, a plurality of blades rotatably mounted on the support about the axis of rotation, the blades being moveable between a retracted position generally parallel with the axis of rotation and a fully deployed position generally perpendicular with the axis of rotation, the blades being connected to the generator such that rotation of the blades in a direction induced by wind causes the generator to produce electricity, and the provision of electricity to the generator rotates the blades, and a controller connected to the generator and configured to deliver a flow of current to the generator that is sufficient to move the blades from the retracted position toward the fully deployed position and insufficient to move the blades all the way to the fully deployed position. The flow of current induces rotation of the blades in the direction induced by wind, which creates a centrifugal force that moves the blades from the retracted position toward the fully deployed position. As the blades move from the retracted position, the blades have increasing exposure to ambient wind to receive additional rotational force from ambient wind, and the additional rotational force being sufficient to, either alone or in combination with the flow of current, move the blades into the fully deployed position.

A wind generator system with a plurality of lightweight, surface area adjustable airfoil/sail blades. Each blade is triangular or wedge shape with a narrow inner edge and a wide outer edge. Each blade includes an inner frame connected to a rigid mast that extends radially from a hub assembly. Each blade includes a curved outer skin layer that extends over the inner frame and configured into air foil shape with a large curved leading edge and a thin trailing edge. The outer skin layer is secured along its leading edge and removeably attached along its trailing edge to the inner frame. Coupled to the outer skin layer is a first linear actuator that when activated, causes the outer skin layer to fold or unfold thereby changing the blade's surface area. The internal frame may include a second linear actuator and a telescopic mast over which the blade slides to increase or decrease the sweep area of the blades. Wind or electrical sensors are coupled to the mast and the retractable cable to automatically control the sweep area and the surface areas.

Provided is a method of setting and clearing a full-power flag in a control process running on a wind turbine controller, the method including (a) acquiring a set of measured values and/or reference values for: rotor speed, output power, blade pitch angle, and activation level of an adaptive flow regulating system, (b) determining that a first condition is fulfilled when the value of the rotor speed equals a speed limit value and the output power reference value equals a power limit value, (c) determining when the blade pitch angle reference value fulfills a pitch condition and the activation level of the adaptive flow regulating system fulfills an adaptive flow regulating condition, or when the measured value of the rotor speed is below the speed limit value, (d) setting the full-power flag, and (e) clearing the full-power flag. Furthermore, a wind turbine controller and a wind turbine including such a controller.

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.

A rotor blade for a wind turbine with an aerodynamic device, and an aerodynamic device is provided. The rotor blade includes a main body defining a pressure side and a suction side of the rotor blade, and includes a main body trailing edge section. The rotor blade includes an aerodynamic device with an attachment section for attaching the aerodynamic device to the main body trailing edge section, an aerodynamic section for influencing the aerodynamic properties of the rotor blade, and a buckling section for controlling the orientation and/or the shape of the aerodynamic section with regard to the main body. The aerodynamic device is configured such that it deforms elastically for a force component acting in flapwise direction on the buckling section, and deforms abruptly if a force component of about the size of the stability limit of the buckling section acts in flapwise direction on the buckling section.

A wind turbine blade, comprising a sensor device for detecting properties of flow-induced noise produced by the blade and an actuator device for emitting an anti-noise signal for at least partially cancelling out the flow-induced noise, wherein the actuator device comprises an aerodynamically shaped housing attached to an outer surface of the blade. The aerodynamically shaped housing of the actuator device reduces a deterioration the aerodynamic efficiency of the blade. Further, the generation of turbulences at sharp edges of the housing is avoided.

A method for mitigating noise during high wind speed conditions of a wind turbine includes providing a backward twist to the outboard region of the rotor blade having an angle of less than 6. The method may also include reducing a tip chord taper within at least a portion of the outboard region of the rotor blade. Further, the method may include increasing a local tip chord length of the rotor blade. In addition, the method may include increasing a torsional stiffness of the outboard region of the rotor blade. As such, a combination of one or more of the blade properties described above are configured to reduce noise associated with high wind speed conditions.

A wind turbine is provided. The turbine includes a support having an axis of rotation, a generator, a plurality of blades rotatably mounted on the support about the axis of rotation, the blades being moveable between a retracted position generally parallel with the axis of rotation and a fully deployed position generally perpendicular with the axis of rotation, the blades being connected to the generator such that rotation of the blades in a direction induced by wind causes the generator to produce electricity, and the provision of electricity to the generator rotates the blades, and a controller connected to the generator and configured to deliver a flow of current to the generator that is sufficient to move the blades from the retracted position toward the fully deployed position and insufficient to move the blades all the way to the fully deployed position. The flow of current induces rotation of the blades in the direction induced by wind, which creates a centrifugal force that moves the blades from the retracted position toward the fully deployed position. As the blades move from the retracted position, the blades have increasing exposure to ambient wind to receive additional rotational force from ambient wind, and the additional rotational force being sufficient to, either alone or in combination with the flow of current, move the blades into the fully deployed position.