Abstract: Methods and systems for reducing an output power of a group of wind turbines are provided. A measure of life usage by at least one component of each of a plurality of the turbines is determined, and is compared to a threshold value for life usage for the component. Power output is preferentially reduced from those turbines having at least one component for which the measure of life usage exceeds the corresponding threshold value.

Abstract: The present invention relates to determining and setting wind turbine type maximum power level (301) and individual wind turbine maximum power level (308) for over-rating control.

Abstract: Embodiments of the invention provide methods, systems, and apparatus for determining a property of wind approaching a wind turbine. A light detection and ranging equipment may emit pulsed radiation into oncoming wind to detect properties of the wind at a plurality of predefined locations. A property of the wind approaching the wind turbine may be determined based on the property of wind measured at at least two predefined locations.

Abstract: A LIDAR or other remote sensing apparatus is mounted on a wind turbine to sense one or more wind parameters. An extreme event detector processing signals from the LIDAR to determine whether a given sensed parameter will, when it arrives at the turbine, exceed a predetermined value and represent an extreme event. On detection of an extreme event, the detector outputs an extreme event signal to a controller. The controller controls overrating of the turbine in response to a variety of sensed parameters and selectively operates the turbine at above rated wind speed. On receipt of the extreme event signal the overrating is overridden to prevent damage to turbine components. The controller may be a power plant controller and the override signal may override only over-rating at the turbine which has detected the extreme event, or a plurality of turbines.

Abstract: A wind turbine variable is controlled by detecting air flow conditions in front of the leading edge of the blade. One or more Laser Doppler Anemometers are mounted on or incorporated into the blade to determine air flow velocity in the region in front of the leading edge of the blade. The measured flow conditions may be used to control the position of a control surface such as a trailing edge flap or the rotor speed. The LDAs may comprise lasers of different frequencies to enable more than one component of flow velocity to be measured.

Abstract: Method of operating a wind power plant including the steps of: operating the wind power plant at an current parameter schedule (Pcurrent(v)) performing a wind prediction of wind data (Vw) for a time frame (?T) extending to a future time T, determining a desired fatigue load level (Fdesired) of a wind power plant component at the future time T, and during operation of said wind power plant generating an updated parameter schedule (Pdesired(v)) to provide the desired fatigue load level (Fdesired) at time T if exposed to the predicted wind conditions (Vw(t)) during said time frame (?T).

Abstract: A wind turbine has a Lidar device to sense wind conditions upstream of the wind turbine. Signals from the wind turbine are processed to detect an extreme event. On detection the system controller takes the necessary evasive action depending on the nature and severity of the extreme condition detected. This may include a significant reduction in power generated, complete shutdown of the generator and yawing of the nacelle and rotor to reduce loading on the rotor blades.

Abstract: A wind turbine power plant comprises a plurality of wind turbines, each having a rated output and under the control of a power plant controller. The power plant also has a rated output which may be over-rated in response to one or more of electricity pricing data, power plant age and operator demand. The power plant controller can send over-rating demand signals to individual turbines. The controllers at the turbines include a fatigue life usage estimator which estimates a measure of the fatigue life consumed by key components of the turbine. If this measure exceeds a target value for any component, over-rating is prevented at that turbine.

Abstract: A LIDAR or other remote sensing apparatus is mounted on a wind turbine to sense one or more wind parameters. An extreme event detector processing signals from the LIDAR to determine whether a given sensed parameter will, when it arrives at the turbine, exceed a predetermined value and represent an extreme event. On detection of an extreme event, the detector outputs an extreme event signal to a controller. The controller controls overrating of the turbine in response to a variety of sensed parameters and selectively operates the turbine at above rated wind speed. On receipt of the extreme event signal the overrating is overridden to prevent damage to turbine components. The controller may be a power plant controller and the override signal may override only overrating at the turbine which has detected the extreme event, or a plurality of turbines.

Abstract: A wind turbine (1) in which the yaw speed of a rotor (4) of the wind turbine (1) is increased, in a direction to reduce yaw error, from a first speed to a faster second speed when at least one of a yaw error threshold and a rate of change in yaw error threshold is exceeded. Yaw error is an amount an axis about which the rotor (4) is rotatable is offset from the wind direction to which the rotor (4) is exposed. As a result, the maximum loads that a wind turbine 1 should withstand may be reduced and lighter wind turbine components result.

Abstract: A wind turbine has a Lidar device to sense wind conditions upstream of the wind turbine. Wind speed signals from the wind turbine are processed to detect an extreme operating gust. The detection is performed by differentiating the axial wind velocity and filtering for a period of time. On detection of extreme operating gust the system controller takes necessary evasive action which may include shutting down the turbine or varying the blade pitch angle.

Abstract: A wind turbine (30) comprising: a rotor (36) having a plurality of blades (38); and a controller (100). The controller (100) is arranged to independently control each of the plurality of blades (38) and/or one or more components of each blade (38) in order to increase a driving moment of each blade (38) independently of other of the blades (38) when speed of wind acting on the wind turbine (30) is below rated. The controller (100) is also additionally or alternatively arranged to independently control each of the plurality of blades (38) and/or one or more components of each blade (38) independently of other of the blades (38) when wind force acting on the blades (38) is above cut-out in order to reduce a mechanical load experienced by at least a part of the wind turbine (30).

Abstract: A wind turbine 30 comprising: a rotor 36 having a plurality of blades 38; and a controller 100. The controller 100 is arranged to independently control each of the plurality of blades 38 and/or one or more components of each blade 38 in order to increase a driving moment of each blade 38 independently of other of the blades 38 when speed of wind acting on the wind turbine 30 is below rated. The controller 100 is also additionally or alternatively arranged to independently control each of the plurality of blades 38 and/or one or more components of each blade 38 independently of other of the blades 38 when wind force acting on the blades 38 is above cut-out in order to reduce a mechanical load experienced by at least a part of the wind turbine 30.

Abstract: Embodiments of the invention provide methods, systems, and apparatus for determining a property of wind approaching a wind turbine. A light detection and ranging equipment may emit pulsed radiation into oncoming wind to detect properties of the wind at a plurality of predefined locations. A property of the wind approaching the wind turbine may be determined based on the property of wind measured at at least two predefined locations.

Abstract: Method of operating a wind power plant including the steps of: operating the wind power plant at an current parameter schedule (Pcurrent(v)) performing a wind prediction of wind data (Vw) for a time frame (?T) extending to a future time T, determining a desired fatigue load level (Fdesired) of a wind power plant component at the future time T, and during operation of said wind power plant generating an updated parameter schedule (Pdesired(v)) to provide the desired fatigue load level (Fdesired) at time T if exposed to the predicted wind conditions (Vw(t)) during said time frame (?T)

Abstract: A wind turbine variable is controlled by detecting air flow conditions in front of the leading edge of the blade. One or more Laser Doppler Anemometers are mounted on or incorporated into the blade to determine air flow velocity in the region in front of the leading edge of the blade. The measured flow conditions may be used to control the position of a control surface such as a trailing edge flap or the rotor speed. The LDAs may comprise lasers of different frequencies to enable more than one component of flow velocity to be measured.