A horizontal axis wind turbine (1) with a wind turbine blade (5) is disclosed, the wind turbine blade (5) comprising a hinge (6) arranged to connect the wind turbine blade (5) to a blade carrying structure (4) of the wind turbine (1), at a non-zero distance from an inner tip (5a) and at a non-zero distance from an outer tip (5b) of the wind turbine blade (5). An outer blade part (7) is arranged between the hinge region and the outer tip (5b), and an inner blade part (8) is arranged between the hinge region and the inner tip (5a). The outer blade part (7) extends from the hinge region along a first direction and the inner blade part (8) extends from the hinge region along a second direction, and the first direction and the second direction form an angle, α, there between, where 0°<α<90°.

The present invention relates to wind energy and can be used to harvest and convert kinetic wind energy into electricity with higher efficiency.

Wind turbine that improves the efficiency of converting wind energy into electrical energy by implementing mechanical design features which harness the entrainment effect by using main rotor blades that are mounted at some distance from the center axis of rotation to allow airflow to pass through its center and to be accelerated by any means (jet fan for example), thus creating higher velocity lower pressure air stream (according to Bernoulli’s law) behind the wind turbine increasing airflow (entrainment effect) through the main rotor blades.

The invention as claimed is a lift-based horizontal-axis wind turbine, the design of which provides higher performance efficiency by extracting more energy from the airflow and at better coefficient of performance and converting it into electrical energy, compared to conventional lift-based horizontal-axis wind turbines of the same turbine rotor diameter.

A wind turbine (1) comprising a tower (2), a nacelle (3) and a hub (7) is disclosed. The hub (7) comprises a blade carrying structure (4) with one or more wind turbine blades (5) connected thereto. Each of the wind turbine blades (5) defines an aerodynamic profile having a chord which varies along a length of the wind turbine blade (5). Each of the wind turbine blades (5) is connected to the blade carrying structure (4) via a hinge (6) at a hinge position of the wind turbine blade (5), each wind turbine blade (5) thereby being arranged to perform pivot movements relative to the blade carrying structure (4) between a minimum pivot angle and a maximum pivot angle. The hinge position is arranged at a distance from the inner tip end (5a) and at a distance from the outer tip end (5b), and the chord at the hinge position is larger than or equal to the chord at the inner tip end (5a) and larger than the chord at the outer tip end (5b).

A method for controlling a wind turbine (1) is disclosed. The wind turbine (1) comprises one or more wind turbine blades (5), each wind turbine blade (5) being connected to a blade carrying structure (4) mounted on a hub (3), via a hinge (6) at a hinge position of the wind turbine blade (5), each wind turbine blade (5) thereby being arranged to perform pivot movements relative to the blade carrying structure (4) between a minimum pivot angle and a maximum pivot angle. A maximum noise level value representing a maximum allowable noise to be generated by the wind turbine (1) is received. An optimal pair of tip speed for the wind turbine (1) and rotational speed of the wind turbine (1) is derived, based on the received maximum noise level value. The pivot angle of the wind turbine blades (5) is then adjusted to a pivot angle which results in the derived optimal pair of tip speed and rotational speed.

The present invention relates to a method for operating a wind turbine (1). The wind turbine (1) comprises one or more wind turbine blades (5), each wind turbine blade (5) being connected to a blade carrying structure (4) mounted on a hub (3), via a hinge (6) at a hinge position of the wind turbine blade (5), each wind turbine blade (5) thereby being arranged to perform pivot movements relative to the blade carrying structure (4) between a minimum pivot angle and a maximum pivot angle. The method comprises the steps of detecting an airborne object entering a predefined zone around the wind turbine (1), comparing a current tip height (H) of the wind turbine (1) to a maximum tip height value, the maximum tip height value representing a maximum allowable tip height under currently prevailing conditions. In the case that the current tip height (H) exceeds the maximum tip height value, a pivot angle (P) of wind turbine blades (5) is adjusted in order to decrease the tip height (H) of the wind turbine (1) to a value below the maximum tip height value.

A joint for the oscillating connection of the rotary shaft of a wind turbine includes a box-shaped hub defining a longitudinal axis and having a pair of holes longitudinally opposite and aligned with each other, a shaft head adapted to be connected to the rotary shaft and having a pair of pivots designed to be inserted in the holes of the hub and having a cylindrical outer surface and a transverse end edge, and a pair of hinges placed at the level of the pair of holes to promote the oscillating connection of the pivots to the hub. Each hinge includes at least one plain bearing mounted on the outer surface of a corresponding pivot, damper elements operatively interacting with the edge of the hub, and a connection system adapted to mutually connect the at least one plain bearing with the damper elements so as to obtain a unitary assembly.

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.

The invention relates to a wind turbine blade having a leading edge erosion shield. The erosion shield comprises an inner layer of a first thermoplastic material, the inner layer being an integral part of the shell body of the wind turbine blade. The erosion shield further comprises an outer layer of a second thermoplastic material attached to the inner layer.

A wind turbine including a plurality of foldable rotor blades coupled to a rotatable hub. A mechanical actuation structure is coupled to the plurality of foldable rotor blades to move the plurality of foldable rotor blades to a deployed state, substantially perpendicular to the horizontal rotor axis, to capture kinetic energy from an incoming fluid flow and move the plurality of foldable rotor blades to a non-deployed state, substantially parallel to the horizontal rotor axis. The mechanical actuation structure including a plurality of toothed wheels, each coupled to one of the plurality of foldable rotor blades at a single fixed rotation point, a threaded rod disposed in cooperative engagement with each of the plurality of toothed wheels and a spring disposed proximate the threaded rod and configured to compensate for the static wind load on each of the plurality of foldable rotor blades. A method is also disclosed.

A wind turbine (1) comprising a tower (2), a nacelle (3) and a hub (7) is disclosed. The hub (7) comprises a blade canying structure (4) with one or more wind turbine blades (5) connected thereto. Each of the wind turbine blades (5) is connected to the blade canying structure (4) via a hinge (6) at a hinge position of the wind turbine blade (5), each wind turbine blade (5) thereby being arranged to perform pivot movements relative to the blade carrying structure (4) between a minimum pivot angle and a maximum pivot angle. The wind turbine (1) further comprises a stop mechanism arranged to move the wind turbine blades (5) to a safe pivot angle in the case of an emergency, the stop mechanism comprising a release mechanism (8, 12, 14) and at least one wire (9, 10) interconnecting the release mechanism (8, 12, 14) and each of the wind turbine blades (5). Activation of the release mechanism (8, 12, 14) causes an abrupt change in a pulling force applied to the wind turbine blades (5) by the wire(s) (9, 10), the change in pulling force causes the wind turbine blades (5) to move immediately to the safe pivot angle.