Abstract:
Methods for controlling tension in mooring lines of a floating offshore structure having a buoyancy structure including one or more water tanks and the buoyancy structure providing excess buoyancy are provided. The methods comprise varying the mass and/or the centre of gravity of the floating offshore structure by varying the quantity of water in one or more of the water tanks. Also, floating offshore structures are disclosed, the structures comprising a buoyancy structure having one or more floater tanks providing excess buoyancy, and a plurality of tensioned mooring lines, and further comprising a control system for increasing and decreasing a quantity of water in one or more of the floater tanks. Also, possible uses of floating offshore structures are provided wherein under standard operating conditions, the floater tanks are at least partially filled with water.
Abstract:
The present wind turbine blade comprises an airfoil structure comprising an airfoil shape, an internal support structure arranged spanwise along the length of the blade within the airfoil structure, and an elastic connection joining a portion of an inner surface of the airfoil structure with a portion of the internal support structure. The airfoil structure can be passively pitched relative to the internal support structure according to aerodynamic pressure distribution at different blade locations.
Abstract:
The present invention generally relates to runner unit of a tidal power plant, and more particular to a blade of the runner unit. The blade according to the invention provides a maximised efficiency of energy production of the tidal power plant during functioning of both direct and reverse modes.
Abstract:
A direct-drive wind turbine comprises a wind turbine rotor and a generator mounted on a frame. The wind turbine rotor comprises a hub carrying blades and the generator comprises a generator stator comprising a track structure and a stator surface connected to the track structure, wherein the stator surface has coil windings, and carriages connected one after the other and adapted to run on the track structure, wherein the carriages carry an electrically magnetically active material facing the stator surface such that when the carriages run along the track structure a magnetic field is generated across an air gap provided between the carriages active materials and the stator coil windings, wherein one or more carriages are directly coupled to the wind turbine rotor by rigid connectors such that rotation of the wind turbine rotor causes displacement of the carriages along the track.
Abstract:
Generator test benches and back-to-back testing systems and methods are disclosed. A test bench (110) may comprise a single fixed structure and a shaft (132). The single fixed structure may include a common base (160) fixed to the ground and a hollow body (115) with a central pillar (117) connecting them. The shaft may be arranged inside the hollow body and may have a first end extending beyond a first opening and a second end extending beyond a second opening of the hollow body. The shaft may be connectable to rotors (124A, 124B) of two generators (120A, 120B). The single fixed structure may be connectable to the stators of the generators (122A, 122B).
Abstract:
A blade pitch system for a wind turbine comprising a motor coupled to a central reduction gearing, wherein a rotatable output of the central reduction gearing is fixed to a mobile link that in use is joined to the blade and allows rotation of the blade around its longitudinal axis and a static part of the central reduction gearing or the motor is fixed to a static link that in use is joined to a wind turbine hub, wherein the system further comprises one or more flexible couplings to couple the central reduction gearing or the motor and the static or the mobile link such that torque about a blade longitudinal axis is transmitted between the blade and the reduction gearing while substantially limiting the transmission of other loads.
Abstract:
Methods of starting a wind turbine from a standstill substantially until generator connection, the wind turbine having a rotor with one or more blades, a pitch system for rotating the blades along their longitudinal axes and a generator operationally connected with the rotor. In standstill, the blades are substantially in a feathered position and the generator is not generating electrical power. The methods may comprise measuring the wind speed representative for the wind turbine and measuring the rotor speed of the wind turbine, and when the rotor speed is not equal to zero, determining the tip speed ratio for the wind turbine, and determining the pitch angle of the blades as a function of the tip speed ratio to optimize the torque produced by the blades of the wind turbine rotor.
Abstract:
Tension leg platform structure for wind turbines It comprises a buoyant structure (110), a platform (120) and at least one anchoring tendon (30) for connecting the platform (120) to a seabed (20) comprising at least a hybrid structure with at least one pre-stressed cable (31) and a pre-stressed concrete structure (32) associated therewith. The anchoring tendons(30) may comprise segments of a given length.
Abstract:
Counterweight system for a wind turbine comprising a hub mounted to a nacelle such that the hub is rotatable around a rotation axis with respect to the nacelle. The counterweight system comprises: a mechanical unit comprising a fixed part and a rotatable part, the fixed part being mountable to the hub in such a way that the rotatable part is rotatable with respect to the hub substantially around the rotation axis of the hub; a drive unit for causing rotation of the rotatable part; a beam coupled to the rotatable part at a first point of the beam in such a way that the beam is arranged substantially perpendicular to the rotation axis of the hub; and a counterweight mass coupled to the beam at a second point of the beam. A method of mounting a blade to a hub by using said counterweight system is also provided.
Abstract:
A wind turbine blade having a blade surface comprising a pressure side and a suction side, comprising one or more flow disturbing devices for provoking air flow separation arranged on the suction side of the blade, wherein the flow disturbing device is removable.