Abstract: A wind turbine includes: a wind turbine rotor; a nacelle supporting the wind turbine rotor rotatably; a yaw rotation part configured to rotate the nacelle; and a yaw control part configured to operate the yaw rotation part in a yaw rewind mode of rotating the nacelle in such a direction that a yaw angle changes toward zero, if an absolute value of the yaw angle exceeds a threshold which is variable in accordance with a wind-velocity parameter representing a magnitude of a wind velocity. The threshold increases with an increase in the wind-velocity parameter.

Abstract: A method of operating a wind turbine power generating apparatus including a wind turbine rotor having a wind turbine blade includes: a step of obtaining a load applied to the wind turbine blade; and a step of selecting an operation mode of the wind turbine power generating apparatus on the basis of the load, from among a plurality of operation modes including a normal operation mode and at least one load-suppressing operation mode in which the load applied to the wind turbine blade is smaller than in the normal operation mode.

Abstract: A method of operating a wind turbine power generating apparatus includes a step of obtaining a wind direction of a wind; a step of obtaining at least one of a wind velocity of the wind or an index of turbulence degree of the wind velocity; and a step of selecting an operation mode of the wind turbine power generating apparatus from among a plurality of operation modes including a normal operation mode and at least one load-suppressing operation mode in which a load applied to a wind turbine blade is smaller than in the normal operation mode, on the basis of whether the at least one of the wind velocity or the index of turbulence degree is at least a threshold. The threshold of the at least one of the wind velocity or the index of turbulence degree is variable in accordance with the wind direction.

Abstract: A controller of a wind turbine for causing the wind turbine to perform rotor turning includes: an input part for receiving a target azimuth angle at which a rotor of the wind turbine is to be stopped; and a pitch control part configured to cause the wind turbine to perform a pitch control to stop the rotor at the target azimuth angle. The pitch control part is configured to: control a pitch angle of a wind turbine blade of the wind turbine so that the rotor rotates at a predetermined rotation speed which is constant, in a first period until the rotor reaches a control-switch azimuth angle immediately before the target azimuth angle; and control the pitch angle so that a rotation speed of the rotor decreases from the predetermined rotation speed in a second period after the rotor reaches the control-switch azimuth angle and before the rotor reaches the target azimuth angle.

Abstract: A wind turbine power generating apparatus includes a wind turbine rotor including at least one blade; a pitch drive part for changing a pitch angle of the at least one blade; a generator configured to be driven by rotational energy of the wind turbine rotor; a circuit breaker for switching a connection state of the generator with respect to a utility grid; and a controller for controlling the wind turbine power generating apparatus. The controller includes a pitch control part configured to control the pitch drive part in a constant rotation-speed control mode for maintaining a rotation speed of the wind turbine rotor at a target rotation speed, before connection of the generator; a connection-condition determination part configured to determine whether a connection determination condition is satisfied; and a connection-command generation part configured to provide the circuit breaker with a connection command to connect the generator to the utility grid.

Abstract: A method of calibrating a load measurement apparatus for measuring a load on a wind turbine blade on the basis of strain data based on strain of a wind turbine blade includes: a strain-data acquisition step of, during a startup of a wind turbine, obtaining a plurality of the strain data for each of a plurality of conditions among which at least one of an azimuth angle or a pitch angle of the wind turbine blade is different from one another; a theoretical load-value acquisition step of obtaining a theoretical load value applied to the wind turbine blade due to own weight of the wind turbine blade, for each of the plurality of conditions, on the basis of the azimuth angle and the pitch angle of the wind turbine blade in each of the plurality of conditions; and a calibration-parameter calculation step of calculating a calibration parameter representing a relationship between the strain data obtained by the load measurement apparatus and the load on the wind turbine blade, on the basis of a correlation between ea

Abstract: An output control device for a wind farm which includes n number of wind turbines includes a WTG output obtaining unit for obtaining a current output Pi of each of the wind turbines; an extractable output calculation unit for calculating an extractable output Pmaxi for each of the wind turbines; a potential output calculation unit for calculating a potential output Ppoti of each of the wind turbines based on a difference between the extractable output Pmaxi and the current output Pi of each of the wind turbines; and a WTG output determination unit for determining an output command value of each of the wind turbines so that a total output PWF of the wind farm becomes closer to an output target value PWF*. The WTG output determination unit assigns an output increase amount to each of the wind turbines and to determine the output command value.

Abstract: A method for detecting damage of a wind turbine blade of a wind turbine rotor having at least one wind turbine blade comprises: a light incident step of allowing light to enter an optical fiber sensor being mounted on each of the wind turbine blade and having a diffraction grating part having a refractive index which is periodically varied in a longitudinal direction of the diffraction grating part; a light detection step of detecting reflected light from the diffraction grating part; an obtaining step of obtaining, from a temporal change of a wavelength of the reflected light received in the light receiving step, a wavelength variation index representing a variation amount of the wavelength; and a damage determination step of determining presence or absence of a damage of the wind turbine blade on the basis of the wavelength variation index calculated in the obtaining step.

Abstract: Provided are a yaw control system and a yaw control method for a wind turbine generator, which are capable of obtaining an accurate value of the yaw direction even when the yaw direction sensor is abnormal.

Abstract: An abnormal vibration detection unit which is capable of stopping a wind turbine generator when excessive vibration is detected. The vibration detection unit has first and second acceleration detectors, a calculation device, a filtering relay, and a safety system which performs an emergency stop of the wind turbine generator in accordance with an output terminal of the filtering relay. The filtering relay has a filter circuit to extract a frequency component from the second analog output signal. The calculation device generates a predicted value of the output signal of the filter circuit part, and detects a failure of the first and second acceleration detectors or the filter circuit part by comparing the predicted value of the output signal of the filter circuit part with a measured value of the output signal of the filter circuit part received from the filtering relay.

Abstract: An output control device for a wind farm which includes n number of wind turbines includes a WTG output obtaining unit for obtaining a current output Pi of each of the wind turbines; an extractable output calculation unit for calculating an extractable output Pmaxi for each of the wind turbines; a potential output calculation unit for calculating a potential output Ppoti of each of the wind turbines based on a difference between the extractable output Pmaxi and the current output Pi of each of the wind turbines; and a WTG output determination unit for determining an output command value of each of the wind turbines so that a total output PWF of the wind farm becomes closer to an output target value PWF*. The WTG output determination unit assigns an output increase amount to each of the wind turbines and to determine the output command value.

Abstract: A wind turbine is provided with a rotor including a plurality of blades and a deicing unit. The deicing unit performs a deicing operation only on one(s) of the plurality of blades, which has an azimuth angle within a predetermined range. The predetermined range is within a range from 90 to 270 degrees, and includes 180 degrees. Therefore, ice scattering is suppressed in deicing the wind turbine blades.

Abstract: An object of the present invention is to provide a wind turbine generator in which a communication channel can be added in communication between a hub and a nacelle, without making a modification to the design of a slip ring. The present invention provides a wind turbine generator in which communication between the hub and the nacelle is performed by superimposing an information signal onto AC power carried over an AC power line between the hub and the nacelle via the slip ring.

Abstract: An object of the present invention is to provide a wind turbine generator in which a communication channel can be added in communication between a hub and a nacelle, without making a modification to the design of a silo ring. The present invention provides a wind turbine generator in which communication between the hub and the nacelle is performed by superimposing an into signal onto AC power carried over an AC power line between the hub and the nacelle via the slip ring.

Abstract: A start-up method of a wind turbine generator includes a step of increasing a pitch angle of a wind turbine blade from a feather pitch angle to a fine pitch angle.

Abstract: The present invention provides a wind turbine generator and a blade pitch angle control method thereof in which an aerodynamic imbalance of a wind turbine rotor at the time of shutdown is further reduced, the maximum load of a wind turbine is further reduced, and the wind turbine generator can be reduced in weight and cost. The wind turbine generator includes a collective pitch angle controller 11 that produces a collective pitch angle demand that is common to blade pitch angles of wind turbine blades, an individual pitch angle producing unit 13 that produces an individual pitch angle demand inherent in each wind turbine blade, multipliers 21 to 23 that multiply the individual pitch angle demand by the individual pitch angle gain; an individual pitch angle gain producing unit 14, and adder 24 to 26 that add collective pitch angle demands to the output of the multipliers 21 to 23 and supply the same to pitch actuators 31 to 33 inherent in the wind turbine blades.

Abstract: A start-up method of a wind turbine generator includes a step of increasing a pitch angle of a wind turbine blade from a feather pitch angle to a fine pitch angle.

Abstract: An object of the present invention is to provide a wind turbine generator in which a communication channel can be added in communication between a hub and a nacelle, without making a modification to the design of a slip ring. The present invention provides a wind turbine generator in which communication between the hub and the nacelle is performed by superimposing an information signal onto AC power carried over an AC power line between the hub and the nacelle via the slip ring.

Abstract: An object of the present invention is to provide an abnormal vibration detection unit which is capable of stopping a wind turbine generator in a case of detecting excessive vibration that poses danger and is designed suitably for the failure detection. The abnormal vibration detection unit comprises first and second acceleration detectors, a calculation device which receives a first analog output signal that is outputted from the first acceleration detector, a filtering relay which receives a second analog output signal that is outputted from the second acceleration detector, and a safety system which performs an emergency stop of the wind turbine generator in accordance with a state of an output terminal of the filtering relay. The filtering relay comprises a filter circuit part that performs filtering process to extract a predetermined frequency component from the second analog output signal.

Abstract: In a conventional technique, a shutdown sequence indicating a sequential operation from a start of the feathering of a wind turbine to the stop is started in response to an alert signal caused by an external factor. In the present invention, when the alert is called off during the shutdown sequence, the shutdown sequence is stopped, and the recovery control by which the pitch angle of the wind turbine blade is controlled toward the fine state is performed. By such a control, the stop period of the wind turbine under the shutdown can be shortened, so that the decrease in the operating rate of the wind farm can be suppressed.