Norskhydro Asa

Hywind As

Statoil Petroleum As

Statoil Asa

Statoilhydro Asa

Finn Gunnar Nielsen

Bjørn Skaare

Bjorn Skaare

Sigmund Askestad

Dagfinn Sveen

Ian Norheim

Kjetil Uhlen

John Olav G Tande

Tor David Hanson

John Olav Giæver Tande

BjØrn Skaare

A method of controlling a turbine of a floating wind turbine structure to reduce fatigue of moorings of the floating wind turbine structure includes curtailing the turbine based on a pitching motion of the floating wind turbine structure and on a wind direction at the floating wind turbine structure relative to an orientation of the moorings of the floating wind turbine structure. Optionally, the curtailment may be further based on a degree of displacement of the floating wind turbine structure from a reference location.

Control system for a floating wind turbine structure

A motion controller for a floating wind turbine with a plurality of rotor blades, is arranged to control a motion of the floating wind turbine in a yaw direction. The controller adjusts the blade pitch of each rotor blade so as to create a net force to control the motions. The controller includes a control action which is proportional to a yaw offset angle and/or a control action which is proportional to an integral of the yaw offset angle.

Controlling motions of floating wind turbines

A method of moving a floating wind turbine relative to a body of water, the floating wind turbine having a buoyant body with a nacelle at the upper end thereof, including the steps of floating the floating wind turbine in the body of water, and towing the floating wind turbine while holding the buoyant body in an inclined position, whereby the nacelle is held clear of the water. As the wind turbine is held in an inclined position, it can be towed through regions of shallower water than if it were in a vertical position.

Method and apparatus for towing offshore wind turbines

The present invention relates to a blade pitch controller for a floating wind turbine structure, wherein the floating wind turbine structure may include a support structure supporting a rotor having a number of blades. The controller may include standard blade pitch control means and active damping means. The standard blade pitch control means is arranged to control a blade pitch using a transfer function between a rotor speed error and the blade pitch. The active damping means is arranged to further control the blade pitch on the basis of a speed of a point on the wind turbine structure by converting the speed of a point on the wind turbine structure into a rotor speed error and using the same transfer function that is used in the standard blade pitch control means to convert the rotor speed error into a correction to the blade pitch.

Blade pitch control in a wind turbine installation

A method in connection with a wind turbine installation for damping tower vibrations, in particular a floating wind turbine installation comprising a floating cell, a tower arranged over the floating cell, a generator mounted on the tower that is rotatable in relation to the wind direction and fitted with a wind turbine, and an anchor line arrangement connected to anchors or foundations on the sea bed. The tower's eigenvibrations, &#x3c9;, are damped by, in addition to control with the controller in the constant power or RPM range of the wind turbine, an increment, &#x394;&#x3b2;, being added to the blade angle of the turbine blades on the basis of the tower velocities, &#x394;Z, so that the eigenvibrations are counteracted. The vibrations in &#x3b2; that have frequency &#x3c9;can expediently be damped by means of a stabiliser with the transfer function H(s) between the tower velocities, &#x394;Z, and the blade angle, &#x394;&#x3b2;, which is such that the loop transfer function H&#x2212;{j&#x3c9;)H(j&#x3c9;)=&#x2212;b, which means that: (I) where 'b' is a variable depending on the moment and thrust characteristics of the turbine blades.

Method for damping tower vibrations in a wind turbine installation

A method for coordinating a floating wind turbine installation. The wind turbine installation includes a buoyant body (), a tower () arranged over the buoyant body, a generator () mounted on the tower which is rotatable in relation to the wind direction and fitted with a wind rotor (), and an anchor line arrangement () connected to anchors or anchor points on the sea bed. Static heeling, &#x3c6;, at full wind load on the wind turbine is as low as possible, but preferably less than 8 degrees, and all eigenperiods for the installation are outside the waves' period range. The eigenperiod in pitch, T(roll, T), is preferably less than 80% of the Teigenperiod in heave. Moreover, the ratio between Tand Tis not close to 0.5 or 1.

Floating wind turbine installation

A procedure and a device in connection with the use of a wind turbine offshore, including a wind turbine () connected via a shaft to a generator (), which is rotationally mounted on a tower (), and a foundation underneath in the form of a float () on which the tower () is mounted. The float is anchored so that it can move freely in the vertical plane via an anchor or a mooring in the form of mooring lines, hinges or tethers (). As a consequence of the effect of the waves on the float, the motion of the wind turbine will act as a damping mechanism on the motion and thus extract energy from the waves. The wind turbine's resonance period can be adjusted by adjusting the platform's center of gravity and/or the tension in the anchor with which the wind turbine is attached to the sea bed.

Growing community of inventors

Bones, Norway

Finn Gunnar Nielsen