A wind turbine system is presented. The wind turbine system includes a wind turbine tower, a plurality of blades, a rotor supported by the wind turbine tower and rotatably coupled to the plurality of blades, a torque control device coupled to the rotor, and a control system programmed to predict an over-speeding time T of an occurrence of an over-speed rotor event based at least in part upon a current rotor acceleration and a current rotor speed, that cannot be compensated by an available counter-torque margin of the torque control device, and, in response, to generate pitch commands for the pitch angles of the plurality of blades to avoid the over-speed rotor event.

An energy generating system for transforming energy of fluid flow into electric energy, the system, at least in operation, comprising: a flow-changing member having a peripheral rim and mounted in a fluid path having a path surface, so as to be at least partially surrounded by said path surface, said flow-changing member being displaceable between a first position, in which at least a portion of the rim is spaced from a corresponding portion of the path surface to a first extent and a second position, in which said portion of the rim is spaced from said portion of the fluid path surface to a second extent greater than said first extent, so that increase of total volumetric flow rate of said fluid above a predetermined threshold to an increased volumetric flow rate is configured to induce displacement of said flow-changing member from said first position toward said second position, thereby causing the volumetric flow rate of said fluid at said spacing to be above said increased volumetric flow rate; and a turbine mounted in fluid communication with said fluid path at a location other than said spacing, whereby said displacement causes the volumetric flow rate of said fluid at said turbine to be below said increased volumetric flow rate.

A brake for a wind turbine includes a disc coupled to and rotatable with the blade support hub of the turbine, and a piston and caliper assembly cooperating with the disc to stop or slow rotation of the blades. In one embodiment, the disc encircles and is rotatable about the shaft of the generator of a vertical axis wind turbine, with one piston and caliper assembly located on each side of the disc. The two piston and caliper assemblies are supported by a platform disposed above a vertical shaft that supports the blade support hub. In another embodiment, the piston and caliper assemblies are coupled to a platform at the end of the horizontally extending tail of a horizontal axis wind turbine.

The present invention relates to a floating wind energy harvesting apparatus for offshore installation, comprising an elongated wind turbine body extending along a longitudinal wind turbine body axis; at least one blade attached to the wind turbine body for converting wind energy to rotation of the wind turbine body around the longitudinal wind turbine body axis; an energy converter coupled to the wind turbine body for converting the rotation of the wind turbine body to electrical energy; and a braking arrangement for controllably reducing a rotational speed of the wind turbine body. The braking arrangement comprises an inlet; an outlet; a water transporting arrangement coupled to the wind turbine body to transport water from the inlet to the outlet in response to rotation of the wind turbine body; and an access control arrangement for controllably preventing water from passing through the water transporting arrangement.

An object of the present invention is to provide a natural energy extraction apparatus comprising a vertical rotating shaft and a float for supporting the vertical rotating shaft, wherein the internal structure of the float is simpler, the float and a mooring apparatus are more compact, and production cost is lower than in the conventional natural energy extraction apparatus. A natural energy extraction apparatus comprises a first float forming a swingable vertical rotating shaft, a second float moored to surround the first float, and a power transmission device attached to the second float to convert rotational kinetic energy of the first float to driving torque for driven equipment, and the natural energy extraction apparatus is installed on a body of water.

A wind turbine is disclosed. The wind turbine includes a shaft rotatable about an axis, a plurality of hubs fixedly attached to the shaft, and a plurality of vanes. The vanes are releasably engaged with each of the plurality of hubs. The vanes disengage from the hubs once the shaft rotates about the axis at a cut-out speed of the wind turbine. In another embodiment, the vanes are releasably engaged with the shaft.

A method for operating a wind turbine is provided. The wind turbine includes a rotor with at least one rotor blade. The method includes determining an actual value of at least one of a first variable indicative of a failure state of the wind turbine and a second variable of the wind turbine correlated to a status of the wind turbine or an ambient status. The method further includes estimating an occurrence of a detrimental overspeed state of the wind turbine from at least one of the determined actual values, wherein a variable speed limit is adjusted based on the result of the estimation. The method further includes operating the wind turbine having regard to the variable speed limit. A control system for performing this method and a wind turbine including the control system is provided.

The invention relates to a turbine and to the implementation method thereof, said turbine comprising a blade mounted such that it can rotate about a central axis and an electromagnetic synchronous machine arranged with the blade in such a way as to modify the angular rotation speed of the blade in order to optimize the mechanical efficiency of the blade as a function of the speed of the incident fluid acting on the blade.

A method for overspeed monitoring of a wind turbine may generally include monitoring an actual rotor speed of the wind turbine while the wind turbine is operating at a current speed setpoint and referencing a dynamic overspeed setting for the wind turbine. The method may also include determining a final overspeed setting to be applied for the wind turbine based on a comparison between the dynamic overspeed setting and a predetermined overspeed setting for the wind turbine. In addition, the method may include comparing the actual rotor speed of the wind turbine to the final overspeed setting, and when the actual rotor speed is equal to or exceeds the final overspeed setting, initiating a control action to adjust an operation of the wind turbine in a manner that reduces the actual rotor speed.

To provide a wind turbine system or a method of controlling the wind turbine system capable of securing stability in pitch control when a sudden change of wind speed is detected and preventing increase of a load on equipment to thereby improve reliability. A wind turbine system includes blades rotating by receiving the wind, a pitch drive device controlling a pitch angle of each blade and a control device outputting a control signal for suppressing a movement of the pitch angle to a fine direction to the pitch drive device when an increase in wind speed for a prescribed amount or more is detected while performing pitch angle control so that a rotational speed of the blades or equipment rotating in conjunction with rotation of the blades maintains a rated rotational speed.