A proactive method and related wind turbine system are provided for reducing vibrations in the rotor blades when the rotor hub is locked against rotation. The method includes determining an initial blade orientation to wind direction and wind parameters for wind impacting the rotor blades. Based on the wind parameters and blade orientation, an angle of attack is determined for the rotor blades that will at least reduce vibrations expected to be induced in the blades from the current wind conditions. With a controller, the rotor blades are pitched to achieve the angle of attack using a pitch control system. The angle of attack is determined and the rotor blades are pitched from the initial blade orientation to the new angle of attack prior to vibrations being induced in the rotor blades.

A method for operating a wind turbine includes determining at least one wind condition of the wind turbine for a plurality of time intervals. The method also includes determining a status of the wind turbine at the beginning of each of the plurality of time intervals. Further, the method includes determining at least one vibration parameter of the wind turbine for one or more preceding time intervals of the plurality of time intervals. Moreover, the method includes predicting whether a trip event is imminent based on the at least one wind condition, the status of the wind turbine at the beginning of each of the plurality of time intervals, and the vibration parameter. Thus, the method further includes implementing a control action for the wind turbine so as to prevent the trip event.

A rotor rotation control system for a wind turbine and a control method thereof are provided. The control system includes a rotation unit configured to drive a rotor of the wind turbine to rotate relative to an engine base of the wind turbine, a driving unit configured to drive the rotation unit, and a processor configured to determine a bending moment load switching position on a rotating shaft of the rotor, and output an adjustment instruction to the driving unit based on the bending moment load switching position.

A method of operating a wind energy installation having a rotor with at least one rotor blade that is angularly adjustable by an adjustment drive. In response to the occurrence of at least one special operating case, in particular at least one malfunction case, the rotor blade is adjusted in a direction of a shutdown position by the adjustment drive. In the shutdown position, a supply of energy from an energy storage device to the adjustment drive is switched off and/or a pitch brake for holding the rotor blade in its current position is closed. In response to at least one activation signal, the rotor blade is adjusted by the adjustment drive in an adjustment mode of operation while the special operating case is still ongoing, in particular while the malfunction case is still ongoing.

The invention relates to a method for controlling the operation of a submersible power plant (1) and a submersible power plant (1). The submersible power plant (1) comprises a structure (2) and a vehicle (3). The vehicle (3) comprises at least one wing (4). The vehicle (3) is arranged to be secured to the structure (2) by means of at least one tether (5). The vehicle (3) is arranged to move in a predetermined trajectory by means of a fluid stream passing the vehicle (3). The vehicle (3) is arranged to change the angle of attack of the at least one wing (4). The method comprises: I: determining if the speed of the fluid passing the vehicle (3) is higher than a predetermined value; or II: determining if the speed of the fluid passing the vehicle (3) is lower than the predetermined value. The vehicle (3) changes the angle of attack for different situations depending on if the speed is higher or lower than the predetermined trajectory.

A wind turbine blade (6) having a span-wise direction between an inner tip region (6a) and an outer tip region (6b), and a chord-wise direction (AA) perpendicular to the span-wise direction is disclosed. The wind turbine blade (6) comprises a hinge (7), an outer blade part (8) and an inner blade part (9). The hinge (7) is arranged to connect the wind turbine blade (6) to a blade carrying structure (5) of a wind turbine (1). The hinge (7) is arranged at a distance from the inner tip region (6a) and at a distance from the outer tip region (6b). The outer blade part (8) is arranged between the hinge (7) and the outer tip region (6b) and the inner blade part (9) is arranged between the hinge (7) and the inner tip region (6a). The inner blade part (9) comprises at least two inner blade portions (20) each having a profile and wherein the inner blade portions (20) are arranged such that the profiles are spaced from each other in the chord-wise direction (AA).

A wind energy harvesting machine with three counter-rotating rotors in a duct is disclosed. The wind energy harvesting machine includes a tower, a duct, a counter-rotating generator with two rotary parts, and three groups of blades. The duct includes supporting static stators in front and rear and a static nose cone in the front. The counter-rotating generator has a main shaft and rotary interior and exterior parts to rotating in opposite directions. Three rotary blade groups including front and rear blade groups rotatable around the main shaft in the same direction, and a middle blade group rotatable in an opposite direction. The front and rear blade groups are displaceable axially along the main shaft and the middle blade group is fixed on the exterior part of the counter-rotating generator.

Described and shown is a process for preparing an emergency energy storage device, with at least one energy storage element for operation, whereby the emergency energy store is designed to provide emergency electrical energy for at least one energy consumer, whereby the energy (E.sub.L) which can be drawn from the emergency energy storage and/or the peak output (P.sub.max) which can be drawn from the emergency energy storage is determined and the operational readiness is established as soon as the energy (E.sub.L) which can be drawn from the emergency energy storage and/or the peak output (P.sub.max) which can be drawn from the emergency energy storage has reached a definable minimum energy value. A process for preparing an emergency energy storage device for operation in which the emergency energy storage is discharged via a discharging device and the heat occurring at the internal resistance (R.sub.i) is used to heat the emergency energy storage device.

A hydraulic turbo machine has a runner that is impinged by water. A diffuser has a multiplicity of guide blades. The diffuser includes a regulating ring for rotating the guide blades. At least one hydraulic servomotor is connected to the regulating ring or to the runner blades. The servomotor has a multiple stage configuration. The housings of the stages are fixedly connected to one another and the pistons of the stages interact only in a part range of the entire adjusting range of the servomotor.

The invention provides a method of shutting down a wind turbine, the wind turbine comprising a rotor with a plurality of blades; and a generator system coupled to the rotor. The method comprises: operating the generator system to generate electrical power and apply a load torque to the rotor; controlling the electrical power generated with a power reference signal; determining that a shutdown of the wind turbine is required; in response to the determination that a shutdown of the wind turbine is required, changing the power reference signal so as to increase the electrical power generated thereby slowing the rotor; determining that a speed of the rotor has reduced below a threshold; and in response to the determination that the speed of the rotor has decreased below the threshold, changing a pitch of the blades to further slow the rotor.