A method for controlling a wind power installation is provided. The method includes operating the installation at a normal operating point at which the installation is not operated in a throttled fashion if there is no request for throttling, and operating the installation at a throttled operating point, in response to a throttle request, with output power which is throttled in comparison with the normal operating point. The method includes changing the operation from the throttled operating point to a reserve operating point at which the installation is operated with higher output power in response to a power increase request. The throttled operating point has a higher tip speed ratio than that of the reserve operating point and is positioned on an associated iso-characteristic curve in the λθ diagram having, at the throttled operating point, a negative characteristic curve gradient.

A method for operating a wind farm having a plurality of wind power installations is provided. The installations each comprise an aerodynamic rotor, and the rotors each have an aerodynamic characteristic value. The method includes: obtaining a setpoint power value of the wind farm, in particular a setpoint value of the electrical power of the wind farm to be fed in, ascertaining an actual power value of the wind farm as the sum of actual electrical powers of the operated wind power installations, determining a permissibility of a power-reduced operating mode of each of the wind power installations of the wind farm on the basis of the associated aerodynamic characteristic value, and operating the wind power installations of the wind farm such that each operated wind power installation is operated in a permissible operating mode and the ascertained actual power value does not exceed the obtained setpoint power value.

A flywheel is attached to a shaft of a turbine. As the shaft rotates, the flywheel swings outwards away from the shaft and regulates the angular velocity of the rotating shaft. In an embodiment, there are multiple flywheels attached to the shaft. In another embodiment there is a first flywheel that controls a second flywheel. In another embodiment, the flywheel has adjustable or centrifugal displacement of counterbalanced masses for effective rotational diameter with effective rotational balance. In another embodiment, a small pilot centrifugal displacement flywheel may control a clutch by rotational velocity and may include a hysteresis control. An example of a clutch may limit that degree to which the arms of the flywheel may be extended and/or retracted. In another embodiment, a small pilot centrifugal displacement flywheel controls the hysteresis of a centrifugal flywheel displacement.

A multistage wind turbine or network of wind turbines with improved and optimized wind-directing, wind-shaping, and wind-power conversion features indicates that the shapes of these features directly affect the ability of the multistage wind turbine to use the power of moving air, such as wind, to spin a rotor and create torque on a rotor shaft to generate electricity. The wind-power-conversion mechanical efficiency described significantly improves upon previous designs by conversion of wind energy into electrical power at a superior price-to-performance ratio compared with existing alternative energy technologies.

Provided is a safety stop valve arrangement of a hydraulic blade pitch system of a wind turbine, including an accumulator arrangement connected over a hydraulic line to a piston of the hydraulic blade pitch system; a redundant set of safety valves arranged between the accumulator arrangement and the piston; a small-orifice restriction nozzle arranged to determine a first rate of hydraulic fluid flow in response to a safety stop input; at least one speed-select valves arranged; and at least one large-orifice restriction nozzle arranged to determine a second rale of hydraulic fluid flow in response to a positive rotor acceleration input, wherein the second rate of fluid flow is faster than the first rate of fluid flow. A safety stop assembly of a wind turbine with hydraulic blade pitch systems and a method of performing a safety stop sequence is also provided.

A method and an apparatus for controlling noise of a wind turbine. The method includes: determining a noise-influencing sector of the wind turbine based on a position of the wind turbine and a position of a noise-influencing site; acquiring a current wind direction; determining whether the wind turbine under the current wind direction operates in the noise-influencing sector; and limiting output power of the wind turbine, and increasing, after the wind turbine goes out from the noise-influencing sector and the output power reaches a rated power, the output power, in a case that the determination is positive.

A method of determining a frequency of an oscillating movement of a wind turbine tower is provided, the wind turbine tower carrying a nacelle and a generator including a stator and a rotor, the oscillating movement causing a rolling movement of the nacelle, the method including obtaining a first signal indicative of rotor speed relative to the nacelle, obtaining a second signal indicative of rotor speed relative to ground, determining a first amplitude spectrum based on the first signal, determining a second amplitude spectrum based on the second signal, determining a difference function based on the first amplitude spectrum and the second amplitude spectrum, and determining the frequency of the oscillating movement of the wind turbine tower as a frequency corresponding to a peak in the difference function. Also provided is a device for determining a frequency of an oscillating movement.

A method of operating a wind turbine generator comprising a plurality of blades, the method comprising iterating the following steps: comparing an indicated rotor speed with a rotor speed target to determine a rotor speed error; generating a modified rotor speed error by applying a control factor to the rotor speed error; controlling the pitch angle of the blades via a pitch control system in accordance with the modified speed error; and altering the control factor in dependence on a size of the indicated rotor speed.

A method for controlling a wind turbine system connected to a power grid. The method comprises generating a wind turbine control signal based on a power control reference for controlling a power output of a wind turbine; monitoring an electrical frequency of the power grid; in response to detecting a change in the frequency in the power grid, activating a fast frequency support method comprising the steps of; adjusting the power control reference to cause an overproduction of power by the wind turbine; the overproduction of power causing a transfer of inertial kinetic energy from the wind turbine to electrical power; wherein the power control reference is determined by applying an adaptive gain function to a measurement of a difference in grid frequency from a nominal level.

The present invention relates to a method for operating a wind power installation, comprising the steps of: sensing at least one angular velocity of the wind power installation, in particular by use of a rotation rate sensor in a hub of the wind power installation, preferably for the purpose of sensing a tilt of the nacelle; sensing a reference value for the at least one sensed angular velocity; determining at least one state variable of the wind power installation from the at least one angular velocity and the reference value; controlling the wind power installation in dependence on the state variable, in particular such that the state variable becomes smaller.