Provided is a control device for controlling a wind turbine, the wind turbine including a rotor and at least one blade being rotatable mounted to the rotor. The control device includes a detecting device being configured to detect an amount of a bending moment of the blade; and a change element having an input and an output, wherein the input is configured to receive the detected amount of the bending moment of the blade and the output is configured to output a response to a differential of the detected amount of the bending moment of the blade. The control device is configured to control the wind turbine based on the response.

A wind turbine and associated control method includes a controller configured with a high speed shaft brake in the generator gear train. The controller receives an input signal corresponding to rotational speed of the high speed shaft, wherein upon the high speed shaft reaching a predefined rotational speed and under a braking condition that calls for the rotor to come to a complete standstill, the controller generates an activate signal to activate the brake. An interlock system is in communication with the low speed shaft sensor and the controller and is configured to override the activate signal when the rotational speed of the low speed shaft is above a threshold value.

A method for operating a wind turbine comprises capturing an actual value of a fed-in power (P.sub.act) and determining a power deviation based on the captured actual value of the fed-in power (P.sub.act). A signal value is set for a correction of a setpoint value for the rotor blade pitch angle when one of the power deviation exceeds a predetermined maximum value and the power deviation exceeds a maximum gradient threshold value over a specified period of time. The signal value is cleared when one of the power deviation falls below a predetermined minimum value and a grid voltage value is located in a predetermined band around a specified target voltage value. A correction value (dβ/dt*) is determined for the setpoint value of the rotor blade pitch angle depending on the power deviation and applied to a rotor blade pitch control when the signal value is set.

An underwater power plant for arrangement in a water current includes at least two rotatable stations and at least one endless traction member connected to the rotatable stations. The at least one endless traction member is configured to rotate the at least two rotatable stations as the endless traction member moves in its lengthwise direction. At least one asymmetric foil is connected to the at least one endless traction member and configured to move the endless traction member in its lengthwise direction as the water current impacts the asymmetric foil. The at least one asymmetric foil has an upper camber side and a lower camber side. The upper camber side is facing in a direction outwards of the at least one endless traction member and the lower camber side is facing in a direction inwards of the at least one endless traction member.

A vertical axis wind turbine with improved safety, production efficiency and greater functional wind speed range. A vertical axis wind turbine comprises turbine blades having geometric characteristics of a “yin yang” symbol when viewed from the top down. The turbine blades are configured to form a scoop portion for catching wind. The surface area of the scoop portion may be dynamically configured to accommodate power production in higher wind speed ranges by dynamically furling the blades to reduce the surface area of the scoop portion as RPM begins to exceed a safe limit. First and second permanent magnet rotor arrays are dynamically positioned above and below an array of stator coils to maximize power generation.

A method for controlling the operation of a wind turbine may generally include monitoring a current yaw position of a nacelle of the wind turbine, wherein the current yaw position is located within one of a plurality of yaw sectors defined for the nacelle. In addition, the method may include monitoring a wind-dependent parameter of the wind turbine and determining a variance of the wind-dependent parameter over time, wherein the variance is indicative of variations in a wind parameter associated with the wind turbine. Moreover, the method may include determining at least one curtailed operating setpoint for the wind turbine when the variance exceeds a predetermined variance threshold, wherein the curtailed operating setpoint(s) is determined based at least in part on historical wind data for the yaw sector associated with the current yaw position.

A turbine (1) for a conduit comprising a turbine unit (13) including a rotor (3), characterized in that the turbine (1) comprises a speed limiting device for said turbine unit (13), which device comprises at least one flexible element (4) connected to the turbine unit (13), so as to limit the flow rate of the fluid passing through the rotor (3) in order to limit the rotational speed of the rotor (3) of the turbine unit (13).

Provided is a protection method for use in fan malfunctions, applicable to an electronic device, and effective in preventing the electronic device from being overheated. The electronic device includes a fan, temperature sensor, and processor. The method includes steps of: limiting the processor's performance, upon determination that not only is the fan's rotation speed greater than or equal to a predetermined upper rotation speed limit, but the electronic device's temperature sensed by the temperature sensor is also greater than or equal to a predetermined upper temperature limit; determining whether the fan's rotation speed is less than or equal to a first restored rotation speed when the fan's rotation speed is determined to be less than the predetermined upper rotation speed limit; and stopping the limiting of the processor's performance when the fan's rotation speed is determined to be less than or equal to the first restored rotation speed.

Provided is a steam turbine overspeed protection system, includes a drive gear arranged to match a rotation speed of a rotor of a steam turbine; a rotating shaft parallel to an axis of the drive gear and capable of rotating at a critical rotation speed; a protective gear arranged on the rotating shaft and forming a lead screw nut mechanism with the rotating shaft, and arranged to be capable of engaging with the drive gear when the rotation speed of the drive gear exceeds the critical rotation speed; and an operating rod connected to the protective gear; wherein, when the drive gear engages with the protective gear, the protective gear can move in the axial direction of the rotating shaft and thereby drive the operating rod to move and produce an action that activates a protection device for preventing steam turbine overspeed.

A method for controlling a wind turbine is disclosed, the wind turbine comprising a set of wind turbine blades (1), each wind turbine blade (1) being provided with at least one air deflector (2) being movable between an activated position in which it protrudes from a surface of the wind turbine blade (1) and a de-activated position. The occurrence of an event causing a change in operational conditions is registered, and a new operating state for the wind turbine is determined, the new operating state meeting requirements of the changed operational conditions. The air deflectors (2) of the wind turbine blades (1) and pitch angles of the wind turbines blades (1) are controlled in order to reach the new operating state for the wind turbine, and in such a manner that the control of the pitch angles of the wind turbine blades (1) is performed while taking information regarding the control of the air deflectors (2) into account.