A flange element for a flange connection with a longitudinal centre axis A includes a flange part and an attachment part. The flange part has a front side with a front surface. The attachment part is adapted for secure attachment to a tubular element comprising a tower section of the tower structure for a wind turbine or a pipe element that is part of an offshare load bearing structure. The flange part is arranged radially on the inside of the flange element and is provided with a flange wedge. The flange wedge includes a flange wedge surface that is part of the front surface, and a flange heel including a flange heel surface that is part of the front surface. The flange wedge surface makes a wedge surface angle α1 and the flange heel surface makes a heel surface angle β with a plane P that is perpendicular to the longitudinal centre axis A of the flange element.

The invention relates to a method and a wind turbine system reducing, preventing or mitigating vibrations due to wind induced vibrations. The wind turbine system includes a wind turbine tower 102, a sensor arrangement 304 for sensing vibrations of the wind turbine tower, a nacelle 104 mounted to the wind turbine tower via a yaw bearing 310 and a control system 306 for controlling yawing of the nacelle relative to the wind turbine 316 tower. The system is adapted for sensing 402 a vibration of the wind turbine tower using the sensor arrangement, providing 404 an input for the control system in response to the vibration of the wind turbine tower as sensed by the sensor arrangement, and providing 406 an output by the control system based on the input, and yawing 408 the wind turbine nacelle based on the 314 output from the control system, and hereby reducing wind induced vibrations of the tower and nacelle, particularly vortex induced vibrations and/or vibrations due to galloping.

Provided is a wind turbine, including a hollow tower carrying a nacelle, and at least one power electronics component emitting electromagnetic waves during operation, in particular an inverter located at the bottom of the tower, wherein the tower acts as a wave guide for an electromagnetic wave generated by the power electronics component, wherein the tower comprises at least one absorber element at least reducing the transport of the electromagnetic wave of the power electronics component along the tower.

Spiral forming methods can be used to join edges of a rolled material along a spiral joint to form conical and/or cylindrical structures. Alignment of the edges of the rolled material can be controlled in a wrapping direction as the material is being joined along the spiral joint to form the structure. By controlling alignment of the edges of the material as the edges of the material are being joined, small corrections can be made over the course of forming the structure facilitating control over geometric tolerances of the resulting spiral formed structure.

A transitioning wind turbine for land or offshore use having a tower base; a wind turbine tower attached to the tower base; a wind turbine attached to the wind turbine tower having a hub and an outer perimeter with spokes disposed between the hub and outer perimeter; a set of vanes carried by the spokes; a generator configured to engage the outer perimeter of the wind turbine and convert a rotational energy of the outer perimeter into power; a lifting tower having a pivot disposed at a proximal end of the lifting tower; a cable attached between the lifting tower and the wind turbine tower; and, wherein the lifting tower is configured to transition from the upright position to the tilted position as the wind turbine tower transitions between the horizontal position to the vertical position.

Supporting structure, in particular for a wind power plant, having at least two sub-segments which are at least partially connected to one another and are respectively formed from a metal plate having a longitudinal extent and a width extent. The longitudinal extent being greater than the width extent, and the sub-segments each having longitudinal edges extending in longitudinal extent and being connected to one another at mutually abutting joint surfaces along the longitudinal edges by a welded joint respectively. The sub-segments respectively have end edges extending in width, the sub-segments being bent along their end edges respectively. The respective welded joint has in sections a thickness which is smaller than a wall thickness of the metal plate and in sections a thickness which corresponds at least to the wall thickness of the metal plate.

A system with a first turbine rotating in a first direction and a second turbine rotating in a second direction, wherein there is negative clearance associated with blades of the first turbine and the blades of the second turbine.

A platform for a wind turbine, the platform including a lift beam for carrying a load of a transport cabin of a tower lift of the wind turbine is provided. By the lift beam being part of the platform, an easier installation of the platform and the lift beam is possible. Furthermore, less components are needed. Another advantage is that the lift beam is installed at a smaller height of the tower where the tower has a larger diameter compared to a conventional lift beam. This increases the available space for lift cables hanging from the lift beam.

The invention relates to a method and a wind turbine system reducing, preventing or mitigating vibrations due to wind induced vibrations. The wind turbine system includes a wind turbine tower 102, a sensor arrangement 304 for sensing vibrations of the wind turbine tower, a nacelle 104 mounted to the wind turbine tower via a yaw bearing 310 and a control system 306 for controlling yawing of the nacelle relative to the wind turbine tower. The system is adapted for sensing 402 a vibration of the wind turbine tower using the sensor arrangement, providing 404 an input for the control system in response to the vibration of the wind turbine tower as sensed by the sensor arrangement, and providing 406 an output by the control system based on the input, and yawing 408 the wind turbine nacelle based on the output from the control system, and hereby reducing wind induced vibrations of the tower and nacelle, particularly vortex induced vibrations and/or vibrations due to galloping.

An apparatus for extracting power includes a track and an airfoil coupled to the track. The track includes first and second elongate sections, where the first elongate section is positioned above the second elongate section. The airfoil is moveable in opposite directions when alternately coupled to the first elongate section and second elongate section.