A control system for yawing a wind turbine rotor relative to the wind and for changing the pitch of rotor blades. A wind direction parameter is measured by a wind direction sensor. The wind direction is calibrated as a function of a predetermined offset parameter, and then adjusted as a function of a wind direction compensation parameter. The adjusted relative wind direction is then used in the determining of a control parameter of the wind turbine. The parameters for the calibration and adjustment of the relative wind direction are obtained from a set of data comprising the wind direction relative to the wind turbine over time and as measured by the wind direction sensor on the wind turbine and as measured by a second wind direction sensor.

Predictively adjusting the pitch of blades and/or sections of a blade based on fluid velocity measurements. In one embodiment, the measurements are obtained of an upstream portion of a fluid flow using a laser Doppler velocimeter. The pitch of the blade(s) and/or blade section(s) are then adjusted to achieve a desired amount of lift or to create a stall-configuration as can be useful for conditions in which an excessive fluid velocity is detected.

A method for controlling a wind turbine includes receiving signals representative of oncoming wind speeds approaching at least a portion of a wind turbine, receiving background noise and signals representative of signal-to-noise ratios corresponding to the signals representative of the oncoming wind speeds, determining an availability-and-atmospheric noise in the signals based on one or more of the signal-to-noise ratios, blade positions of blades of the wind turbine, and the yaw position of a nacelle of the wind turbine, determining a wind incoherence noise in the signals due to a change in the oncoming wind speeds while approaching at least the portion of the wind turbine, determining a net measurement noise in the signals based on the background noise, the availability-and-atmospheric noise, and the wind incoherence noise, and controlling the wind turbine based at least on the signals representative of the oncoming wind speeds and the net measurement noise.

A method for identifying a blade run-away condition in the event of a pitch system failure of a rotor blade of a wind turbine includes determining, via one or more sensors, an actual rotor loading of the wind turbine. The method also includes determining, via a turbine controller, an estimated rotor loading of the wind turbine based on at least one of one or more operating conditions of the wind turbine or one or more wind conditions of the wind turbine. Further, the method includes determining a difference between the actual rotor loading and the estimated rotor loading. The method also includes determining whether the blade run-away condition is present based on the difference. The method may also include implementing a corrective action that mitigates loads caused by the blade run-away condition.

A configuration is provided which includes: a reference light source to emit laser light; an optical phase modulator to perform phase modulation of transmission light of the laser light on the basis of a linear-phase-modulation signal having a first frequency component and a second frequency component; an optical intensity modulator to modulate light intensity of the transmission light on the basis of a pulsed light generation signal for generation of pulsed light; first and second optical antennas to emit the transmission light to a space and receive reflected light from a first point and a second point; an optical receiver to perform heterodyne detection on light obtained by mixing received light and local oscillation light; and a signal processor to separate a received signal on the basis of the first and the second frequency components.

A wind turbine device including: a blade rotation speed calculator to calculate a blade rotation speed of blades of a wind turbine, the blades crossing laser light emitted by a wind measurement lidar device installed on a wind turbine nacelle of the wind turbine; a coming wind velocity calculator to calculate a coming wind velocity on a basis of a wind velocity in line-of-sight direction of the laser light, the wind velocity being obtained from the wind measurement lidar device; and a start assist controller to control a start assist for starting rotation of the blades on a basis of the blade rotation speed calculated by the blade rotation speed calculator and the coming wind velocity calculated by the coming wind velocity calculator.

The present invention relates to controlling a wind turbine with an updated power coefficient. The updated power coefficient being adjusted by a degradation function which is determined in an iterative adjustment process. The wind turbine is controlled in partial load operation mode based on a tip-speed ratio (TSR) tracking scheme based on an estimated wind speed. The iterative adjustment process comprises operating the wind turbine to obtain a measurement set. The degradation function that represents the values of the measurement set is calculated and assigned to the mean operating TSR of the measurement set. The iterative process is continued until a difference between the selected TSR and the mean operating TSR is below a preset difference. A continuous degradation function for a range of the mean operating TSR value(s) is thereby obtained to determine an updated power coefficient to be used as the operating power coefficient.

Predictively adjusting the pitch of blades and/or sections of a blade based on fluid velocity measurements. In one embodiment, the measurements are obtained of an upstream portion of a fluid flow using a laser Doppler velocimeter. The pitch of the blade(s) and/or blade section(s) are then adjusted to achieve a desired amount of lift or to create a stall-configuration as can be useful for conditions in which an excessive fluid velocity is detected.

A method is provided for operation of a wind turbine having rotor blades attached to a hub, wherein a controller compensates for torsionally induced blade twist. The method includes operating the wind turbine according to a rated power output curve and maximum design thrust value, and periodically or continuously detecting for induced torsional twist in the rotor blades. Upon determination of torsional twist being induced in the rotor blades, the method includes adjusting the maximum thrust value in the control program to compensate for the induced twist. The wind turbine controller then controls pitch of the rotor blades as a function of the increased maximum thrust value so that power output of the wind turbine is not unnecessarily limited or increased by the induced twist on the rotor blades.

A configuration is provided which includes: a reference light source to emit laser light; an optical phase modulator to perform phase modulation of transmission light of the laser light on the basis of a linear-phase-modulation signal having a first frequency component and a second frequency component; an optical intensity modulator to modulate light intensity of the transmission light on the basis of a pulsed light generation signal for generation of pulsed light; first and second optical antennas to emit the transmission light to a space and receive reflected light from a first point and a second point; an optical receiver to perform heterodyne detection on light obtained by mixing received light and local oscillation light; and a signal processor to separate a received signal on the basis of the first and the second frequency components.