A method for rebuilding an electric supply grid of a grid operator by means of at least one wind power installation, wherein the electric supply grid has a first grid section and at least one further grid section, wherein the first grid section is connected to the at least one wind power installation and has a first grid nominal voltage, the first grid section is coupled to the at least one further grid section via at least one switching device in order to transmit electric energy between the grid sections, wherein the at least one switching device is set up to disconnect the first grid section from the at least one further grid section in the event of a fault, comprising the steps of operating the at least one wind power installation in an observation mode if the fault occurs, wherein the wind power installation does not feed the first grid section in the observation road and a status of the first grid section is checked, and operating the at least one wind power installation in a grid rebuilding mode if the first grid section has a grid rebuilding voltage, and operating the at least one wind power installation in a normal operating mode again as soon as the fault has passed.

A system and method employing wear debris sensors to monitor the operation of a lubricated mechanical system such as a gearbox (e.g., in a wind turbine), a transmission or an engine in order to control operation of the gearbox in order to reduce damage and/or extend the useful life of the gearbox.

A method is provided for braking a rotor of a wind turbine. The rotor comprises rotor blades. The wind turbine comprises a pitch adjustment system for adjusting a pitch of the rotor blades. The method comprises detecting a system failure of the pitch adjustment system, estimating a current wind speed, estimating an available brake torque and estimating a required brake torque, based on the estimated current wind speed. The method further comprises determining a suitable point in time for activating a rotor brake, based on the estimated available brake torque and the estimated required brake torque. The rotor brake is then activated at the determined suitable point in time.

A method for controlling a wind farm, which is operated by means of a wind farm control unit and comprises a multiplicity of wind power installations having wind power installation controllers and being connected to one another via a common wind farm grid, which is connected to an electrical power supply grid of a grid operator by means of a wind farm transformer, comprising the following steps: reception of at least one fault bit at the wind farm control unit, in particular at least one fault bit of the grid operator, deactivation of all external setpoint value specifications at the wind farm control unit apart from those of the grid operator after reception of the fault bit, activation of a closed-loop fault case control implemented in the wind farm control unit after successful deactivation of all external setpoint value specifications apart from those of the grid operator.

The present disclosure provides a control method, device and system for a wind turbine. The control method includes: acquiring current working conditions of a power system, a yaw system and a communication system of the wind turbine when a typhoon warning signal is received; determining a target control strategy corresponding to the current working conditions according to a preset corresponding relationship between control strategies and working conditions of the power system, the yaw system and the communication system, wherein the control strategies may include an active windward strategy for controlling the yaw system to face typhoon wind direction, a controlled passive leeward strategy for controlling the yaw system to face opposite to the typhoon wind direction, and a passive leeward strategy for adjusting the yaw system to face opposite to the typhoon wind direction; and controlling the wind turbine by using the target control strategy.

A structure for a turbine, the structure comprising a body having a multi-layer construction including an interior layer with substantially uniform concentrations throughout of facultative anaerobic organisms (FAO) that have gene sets capable of producing the enzyme urease and/or the proteins purloin, lustre A and perlustrin, along with glucose, and non-uniform concentrations throughout of a structural composition, the structural composition including a chitin-based component with silk fibronectin and water; an exterior layer of urea, water, calcium ions and facultative anaerobic organisms (FAOs) including urease, aragonite; and a binding layer of conchiolin protein intermediate the interior layer and the exterior layer. The facultative anaeorobic organisms (FAOs) are organisms classified in one of the Saccharomyces, Escherichia and Bacillus genuses.

The present invention relates to control of wind turbines in a situation where a fault condition is detected. Control of a wind turbine is described where a control trajectory and a safe-mode trajectory are calculated based on the current operational state of the wind turbine. If the fault condition is detected the wind turbine is controlled using the safe-mode trajectory, otherwise, the normal operation of the wind turbine is continued where the wind turbine is controlled using the control trajectory.

Embodiments herein describe validating an emergency stop signal before activating a brake within a wind turbine. The emergency stop signal is received from a control node of a plurality of control nodes distributed throughout the wind turbine, and the emergency stop signal indicates that the wind turbine should be shut down. The wind turbine is shut down by transmitting a shutdown signal to the plurality of control nodes. Upon determining there is no indication a person is present within the wind turbine, the emergency stop signal is validated. Additionally, upon determining the emergency stop signal is valid, a brake within the wind turbine is activated to bring the rotor to a stop.

A method for a wind turbine in an emergency mode. In that case a change in the wind direction and/or a force exerted on the wind turbine is detected and at least one of the rotor blades is adjusted in dependence on the change while maintaining the yaw angle of the yaw setting. A control means for a wind turbine and a wind turbine.

A hydroelectric generation system includes a fluid machine disposed in a penstock or channel, a generator driven by the fluid machine, and a control unit configured to generate a predetermined torque in the generator. Fluid flows through the penstock or channel. The penstock or channel has a main path in which the fluid machine is disposed, and a detour disposed in parallel with the main path. The detour includes an on-off valve. The on-off valve is opened when not electrified, and closed when electrified.