A wind turbine rotor blade includes a deformation arrangement, which deformation arrangement includes a tensioning device; an anchor; a cable extending in a longitudinal direction along a surface of the pressure side of the rotor blade, wherein the cable has an inboard end attached to the tensioning device and an outboard end attached to the anchor, which anchor is positioned further outboard than the tensioning device and wherein the tensioning device is configured to adjust the tension of the cable in response to a tensioning device control signal to effect a deformation of the rotor blade in the upwind direction. A wind turbine and a method of operating a wind turbine is also provided.

A wind turbine rotor blade is provided including a deformation arrangement, which deformation arrangement includes a plurality of linear actuators, wherein each linear actuator is arranged at the suction side of the rotor blade, wherein a longitudinal axis of a linear actuator is aligned with a longitudinal axis of the rotor blade, and wherein each linear actuator is realized to alter its length in response to an excitation signal; and an interface configured to receive a corrective control signal and to issue excitation signals to the linear actuators on the basis of the corrective control signal. Also provided is a wind turbine and a method of operating a wind turbine.

In a first aspect of the invention there is provided a wind turbine blade comprising a blade shell that extends in a spanwise direction from a root end to a tip end, and in a chordwise direction from a leading edge to a trailing edge. The blade shell comprises a spar cap formed from a plurality of substantially planar strips of reinforcing material, the strips being arranged in a plurality of stacks extending longitudinally in the spanwise direction and arranged side-by-side in the chordwise direction. In each stack an uppermost strip defines an upper surface of the stack, a lowermost strip defines a lower surface of the stack, and longitudinal edges of the stacked strips define side surfaces of the stack. The blade further comprises a retaining clip comprising a plurality of side-by-side substantially U-shaped sections. The U-shaped sections each comprise a pair of mutually-spaced side portions defining a stack-receiving region therebetween, and the side portions are joined by a bridging portion. At least some of the stacks are located in the stack-receiving regions of the retaining clip, such that the side portions of the U-shaped sections abut side surfaces of the stacks. Each U-shaped section of the retaining clip is inverted with respect to its neighbouring U-shaped section(s) such that the bridging portions of the respective U-shaped sections extend alternately across the upper and lower surfaces of the stacks in the chordwise direction.

The present disclosure relates to devices for wind turbine blades and methods for reducing vibrations in wind turbines. More particularly, the present disclosure relates to devices for mitigating vortex induced vibrations and stall induced vibrations, wind turbine blades comprising such devices, and methods for reducing wind turbine vibrations when the wind turbine is parked, especially during wind turbine installation and/or maintenance. A method for mitigating vibrations of a parked wind turbine comprises arranging a device in an inactive state with a wind turbine blade; and causing the device to transition to an active state in which the device grips the wind turbine blade more strongly than in the inactive state.

A dynamic vibration absorber includes a frame configured for mounting to a moveable structure; a flywheel mounted on a first shaft; and a first converter adapted to convert a linear displacement of the frame into rotation of the first shaft; including a rotary damper mounted on a second shaft; and a second converter adapted to convert a rotational velocity of the first shaft into a rotational velocity of the second shaft.

It is described a method of operating at least one adaptable airflow regulating system (13) of at least one rotor blade (15) of a wind turbine (1) connected to a utility grid (6), the method comprising: receiving information (10) regarding a grid disturbance; adapting, in particular during a disturbance duration, the airflow regulating system (13) based on the information (10), while the wind turbine (1) stays connected to the utility grid (6).

A load mitigation arrangement of a non-mounted rotor blade, includes at least one actuatable lift-modification device arranged on a surface of the rotor blade; a monitor configured to estimate the magnitudes of loads acting on the non-mounted rotor blade; a controller configured to actuate the lift-modification device on the basis of the estimated magnitudes to mitigate the loads acting on the non-mounted rotor blade. Further provided is a rotor blade assembly, and a method of performing load mitigation on a non-mounted rotor blade.

A root portion for a wind turbine blade is provided, including: an inner wall, an outer wall, a filler, an inner volume, mounting inserts, and a transversal holding arrangement, wherein the transversal holding arrangement includes at least one inlay beam extending from the inner wall and/or the outer wall into a mounting insert hole of at least one mounting insert for holding the mounting insert in the root portion during operation of the wind turbine blade, and wherein the mounting insert hole is a through hole and the at least one inlay beam extends from the inner wall through the mounting insert hole to the outer wall. A wind turbine blade with the root portion, a method of producing the root portion and a method for modifying a root portion is further provided.

A wind turbine with a retractable blade and a thrust force transmission structure provides an adjustable blade length system that maintains the airfoil shape and does not negatively impact aerodynamic efficiency. Thrust Force Transmission Structure that directly transfers the thrust forces from the blade tip to the hub, thereby reducing bending stresses and acting as a damper. This system significantly reduces the torque experienced at the root section, leading to a lighter blade design and extended blade lifespan.

The disclosure relates to a piston accumulator comprising an accumulator housing and a separator piston which is longitudinally moveably arranged therein and separates two media chambers from one another within the accumulator housing, wherein the accumulator housing is elastically formed in a sandwich-type structure from individual, partially differing layers in such a way that, with the influence of at least one external force, it allows for a curvature as a whole, starting from a starting state, and it returns to the starting state with the removal of the respective force.