A wind turbine offshore installation method of installing a wind turbine using a semi-submersible type floating substructure includes: a step of towing the semi-submersible type floating substructure on which the wind turbine is erected to an installation target site on a sea; and a step of coupling the wind turbine and a spar type floating substructure for supporting the wind turbine on the sea at the installation target site to install the wind turbine on the sea.

The invention relates to a structure (2) for supporting a wind turbine tower (1) provided with a housing (7) for fitting therein the foot of the tower (1), a main axis (Γ) being defined on the platform (2) which coincides with a main axis of the tower (1), and which comprises a body with a constant cross-section and internal walls (8) and intermediate walls (10) joined by internal radial ribs (11) perpendicular to the internal wall (8) whose plane passes through the main axis (Γ), such that at the intermediate wall (10) first joining nodes (12) are defined between the intermediate wall (10) and radial ribs (11), the intermediate wall (10) and an external wall (9) being joined by reticular ribs (14 and 15). This structure provides an optimal transmission of forces. The invention likewise relates to methods for manufacturing, assembling and installing the structure.

A support structure for a wind power generation device comprises: a plurality of floats that can float on the surface of water or in the water; a connecting member having one end connected to one of the floats and the other end connected to another of the floats among the plurality of floats; a support platform that is provided between the plurality of floats and supports the bottom end of a tower part of the wind power generation device; a linear wire member having one end connected to one of the floats and the other end connected to the support platform; and a support member that is provided on the floats or on the connecting member and supports the tower part, which is supported on the support platform, from a lateral direction while the support member being movable along the axial direction of the tower part.

A stiffening member for a protective housing assembly which defines a bore for receiving a utility line. The housing assembly includes a first body member, and a second body member arranged adjacent to one another to define immediately adjacent sections of the bore which surrounds the utility line. The stiffening member includes a first side for engagement with the first body member, and a second side for engagement with the second body member wherein pedestals extend from the first side of the stiffening member in a first direction away from the second side.

An offshore wind turbine including a tower, a transition piece and a lifting apparatus for operating a lift inside the wind turbine is provided. The tower includes an inner platform at the bottom end of the tower. The transition piece includes a hang-off platform. The lifting apparatus includes a plurality of wires, a plurality of tensioners, one or more brackets attached to the inner platform and movable between at least a first operative configuration in which the plurality of tensioners are attached to the one or more brackets and the lift is movable from the first station at the inner platform towards the upper end of the tower, a second retracted configuration in which one or more brackets allows the lift to move between the first and the second station, the plurality of tensioners being attached to the hang-off platform.

Methods and systems for operating a stable platform in a far-offshore deep-sea environment. The platform can advantageously be a wind power generation station. A structural framework carries (for example) the wind turbine in an elevated position. Multiple points on the floating structure are connected both to a surface float and to a deep mass (e.g. an enclosed volume of seawater).

A controller is provided for a floating wind turbine including a rotor with a number of rotor blades connected to a generator. The controller includes an active damping controller for calculating one or more outputs for damping both a first motion of the floating wind turbine in a first frequency range and a second motion of the floating wind turbine in a second frequency range based on an input of the first motion and an input of the second motion, The controller is arranged to calculate an output for controlling a blade pitch of one or more of the rotor blades and/or for controlling a torque of the generator based on an actual rotor speed, a target rotor speed, and the one or more outputs from the active damping controller such that both the first motion and the second motion will be damped.

Embodiments herein describe operating wind turbines in an offshore park to provide auxiliary power to a local AC grid or to an onshore grid during a grid malfunction. In one embodiment, the offshore park is coupled via a HVDC link to an onshore grid. When the HVDC link is down, a substation in the park includes a backup generator for creating a weak grid for powering auxiliary systems in a pilot turbine. The wind turbines in the park can switch to an auxiliary control system help power the auxiliary systems in the substation and in other turbines. In another embodiment, the offshore park is AC coupled to an onshore grid using a transformer in the substation. The wind turbines can participate in a brown or black start following a grid fault by switching to operating using the auxiliary control system.

The invention relates to a wind driven power plant comprising a nacelle having a nacelle cover and a helicopter hoisting platform, the nacelle further comprising a hatch extension and a hatch cover, the hatch extension being arranged between the nacelle cover and the hatch cover, wherein the hatch extension has a channel-like shape, wherein the hatch cover is mounted on top of the hatch extension, and wherein a the hatch extension provides a distance between the hatch cover and the nacelle cover.