Abstract:
Wind turbines are provided comprising a support structure having a tower and a nacelle mounted on the support structure. A first region (damper region) of the wind turbine including at least a first part of the nacelle is flexibly coupled to a second region (to be damped) of the wind turbine including at least the support structure. Methods are also provided for determining a suitable stiffness of the flexible coupling of the damper region to the region to be damped of any one of said wind turbines. These methods comprise determining a modal mass of the region to be damped depending on a given tower bending mode; and determining the stiffness of the flexible coupling of the damper region to the region to be damped depending on the calculated modal mass of the region to be damped and on the mass of the damper region.
Abstract:
Wind turbine blades comprising a deformable trailing edge (DTE) section extending chordwise and spanwise, wherein the DTE section is split in a suction side subsection and a pressure side subsection by one or more slits, wherein the DTE section comprises one or more actuators acting on at least one of the suction side and pressure side subsections, and wherein the suction side and pressure side subsections and the actuators are arranged such that deformation of one of the subsections is associated with a substantially corresponding deformation of the other subsection.
Abstract:
Floating offshore structures comprising a buoyancy structure arranged such that in use it remains below the sea level, and a tower, wherein the buoyancy structure is attached to the tower by a substantially tubular connecting structure, wherein one or more through channels are provided in the buoyancy structure, the through channels being traversing the buoyancy structure and extending from a bottom portion of the buoyancy structure to an inner portion of the connecting structure, the through channels being dimensioned such that sea water can flow into and out of the connecting structure with variations of the sea level. The application further relates to floating offshore structures comprising a wind turbine and to methods of reducing buoyancy variations in such floating offshore structures.
Abstract:
Wind turbine blade comprising a shape modifiable airfoil section that extends both chordwise and spanwise and has a not modified default shape, a conduit that extends from the inside of the blade towards the outside of the blade, and an outer part comprising a flow regulator that is located at the shape modifiable airfoil section and blocks the conduit when the shape modifiable airfoil section presents its default shape, and does not block the conduit when the shape modifiable airfoil section presents a modified shape. In the latter situation the conduit is opened to the outside of the blade and a device for exchanging a fluid between the inside and the outside of the blade is thus defined.
Abstract:
The method relates to the fabrication of a Francis-type runner for a hydraulic machine. The Francis-type runner includes: a runner band including at least two elements partially defining the runner band, a runner crown including at least two elements partly defining the runner crown, and a plurality of blades extending between the runner crown and the runner band. The blades are each fitted in between two elements of the runner band and between two elements of the runner crown. The method includes fabricating separately the blades, the elements of the runner band and the elements of the runner crown. All the elements of the runner band are then welded to the blades using an electron beam welding method. All the elements of the runner crown are then welded to the blades using an electron beam welding method.
Abstract:
Method of operating a variable speed wind turbine as a function of wind speed are disclosed, the wind turbine having a rotor with a plurality of blades, a generator, pitch mechanisms for rotating the blades around their longitudinal axes, and a system for varying a torque of the generator. The method comprises at a first moment in time estimating representative future wind speed values from the first moment in time up to a second moment in time, the second moment in time being equal to the first moment in time plus a predetermined finite period of time, and using a control strategy to optimize a cost function indicative of an energy output of the wind turbine based on the estimated representative future wind speed values by controlling the torque of the generator and the pitch angles of the blades. Wind turbines suitable for such methods are also disclosed.
Abstract:
The present application describes a method for welding two parts to each other. The two parts are made from steel having a high thermomechanical yield strength. The welding method includes a welding step in which a weld bead is created inducing a heat-affected zone to appear. The method also includes a heat treatment step having a heating step, during which at least one portion of the weld bead and the HAZ is gradually heated to a treatment temperature; then a holding step in which the portion of the weld bead and the HAZ is kept at the treatment temperature; then a cooling step in which the HAZ and the weld bead are gradually cooled and pass from the austenitic transformation end temperature to the martensitic transformation end temperature of the steel of the parts in a time between 7.5 s and 8.5 s, and pass from the austenitic transformation end temperature to the martensitic transformation end temperature in a time shorter than 15.5 s. The present application also describes a penstock obtained with such a method.
Abstract:
A tower portion for a wind turbine includes at least one wall segment and at least one opening segment. The opening segment includes an opening, one or more inner edges, two side edges, an upper edge and a lower edge, the opening being delimited by the one or more inner edges. The wall segment is shaped as less than a full 360° ring. The opening segment is coupled with the wall segment by the side edges. The opening segment and the wall segment form segments of a ring and when coupled form a full 360° ring. The opening segment has a variable thickness increasing from the side edges to the inner edges.
Abstract:
A permanent magnet rotor comprising a rotor rim and a plurality of permanent magnet modules arranged on the outer or inner circumference of the rotor rim, the permanent magnet modules extending generally along an axial direction and being of substantially constant axial-cross section, and comprising a base adapted to be fixed to the rim of the generator rotor, one or more permanent magnets, and one or more pole pieces, wherein each of the permanent magnets has a circumferential magnetic orientation and is substantially rectangular in axial cross-section and wherein each of the permanent magnets is inclined with respect to the central radial plane of the module.
Abstract:
An impulse air turbine arrangement for use with a reversing bi-directional air flow in a wave power plant comprises an axial flow turbine rotor with volutes mounted one each side of the turbine rotor to direct the reversing air flow to and from the turbine rotor. Each volute extends circumferentially with respect to the turbine axis between a radially outer opening and a radially inner opening. The radially outer opening is oriented for input/output of the air in a tangential direction and the radially inner opening is oriented axially to impinge/receive swirling air flow onto/from the turbine rotor.