Abstract: A method and system for improving the balance of a rotor in a wind turbine, including; determining blade load data associated with a selected rotor blade pair; determining, based on the blade load data, pitch imbalance data associated with the selected rotor blade pair, wherein the pitch imbalance data associated with a rotor blade pair is based on measurements of at least blade loading, rotor speed and wind speed; and, determining and applying pitch control inputs to one or both of the selected rotor blade pair in order to reduce the severity of the rotor imbalance.

Abstract: The invention relates to a control system for a wind turbine. The wind turbine comprises a power generator configured to generate power dependent on a power reference and a pitch system configured to adjust the pitch of a blade of the wind turbine dependent on a pitch request. The control system comprises a controller configured to determine the pitch request dependent on an adjustable gain. A gain scheduler comprised by the control system is configured to set the adjustable gain to an increased gain value if a rate of change of the power reference, e.g. an external power reference, exceeds a threshold.

Abstract: Embodiments herein describe using a tower damping system to reduce oscillations in a wind turbine. To do so, the dampening system may use a metric that is decoupled from the activation strategy in order to control the blade pitch and avoid or mitigate feedback loops. In one embodiment, the dampening system measures a force on the turbine that is correlated to a fatigue loading on the tower. Furthermore, the turbine may perform a calculation to decouple the force from the activation strategy. That is, the turbine determines the value of the force as if the damping system was not activated or present. In addition, the dampening system uses the current wind speed and a wind distribution to generate a pitch reference value. The dampening system may use both the pitch reference value and the fatigue loading on the tower to reduce the tower oscillations.

Abstract: The invention relates to a control system for a wind turbine. The wind turbine comprises a power generator configured to generate power dependent on a power request. The control system comprises a ramp rate limiter configured to restrict a rate of change of the power request according to a rate of change limit and configured to determine the rate of change limit dependent on a power difference between the power request and an estimated available wind power.

Abstract: The invention relates to a method of controlling a wind turbine comprising one or more blades attached to a rotor hub, the one or more blades being arranged to pitch relative to the hub, the method comprising the steps of obtaining a blade load signal comprising data on an absolute load on the one or more blades; processing the blade load data to detect a high thrust wind event, and generating a control signal comprising a pitch contribution for affecting the blades to pitch out of the wind in response to the detected wind event. The invention also relates to a wind turbine, a control system for a wind turbine and a computer program product being adapted to enable a computer system to perform the method of the invention.

Abstract: The invention relates to a control system for a wind turbine. The wind turbine comprises a power generator configured to generate power dependent on a power request. The control system comprises a ramp rate limiter configured to restrict a rate of change of the power request according to a rate of change limit and configured to determine the rate of change limit dependent on a power difference between the power request and an estimated available wind power.

Abstract: A wind turbine is controlled in response to an estimate of vertical and/or horizontal wind shear. A tilt moment is estimated from flapwise and edgewise blade bending moments, azimuth and blade pitch positions and used to estimate vertical wind shear. A yaw moment is also estimated from flapwise and edgewise blade bending moments, azimuth and pitch position and used to estimate horizontal wind shear. A tip speed ratio is determined from an estimate of wind velocity over the rotor plane and is used to set a blade pitch angle which is passed to a blade pitch controller. The pitching may be collective or individual. In the latter case, the tip speed ratio is determined from a plurality of rotor plane positions to derive a cyclic pitch reference for each blade.

Abstract: The invention relates to a control system for a wind turbine. The wind turbine comprises a power generator configured to generate power dependent on a power reference and a pitch system configured to adjust the pitch of a blade of the wind turbine dependent on a pitch request. The control system comprises a controller configured to determine the pitch request dependent on an adjustable gain. A gain scheduler comprised by the control system is configured to set the adjustable gain to an increased gain value if a rate of change of the power reference, e.g. an external power reference, exceeds a threshold.

Abstract: Embodiments herein describe using a tower damping system to reduce oscillations in a wind turbine. To do so, the dampening system may use a metric that is decoupled from the activation strategy in order to control the blade pitch and avoid or mitigate feedback loops. In one embodiment, the dampening system measures a force on the turbine that is correlated to a fatigue loading on the tower. Furthermore, the turbine may perform a calculation to decouple the force from the activation strategy. That is, the turbine determines the value of the force as if the damping system was not activated or present. In addition, the dampening system uses the current wind speed and a wind distribution to generate a pitch reference value. The dampening system may use both the pitch reference value and the fatigue loading on the tower to reduce the tower oscillations.

Abstract: A method of controlling a wind turbine comprising blades attached to a rotor hub for rotation in a rotor plane and a control system for individually pitching the blades relative to the hub. The method comprises dividing the rotor plane into a number of sectors, determining the individual sectors for each blade during the rotation by means of an azimuth angle sensor, and obtaining blade sensor data from a blade sensor on an individual blade relating to a sector, and comparing the obtained data with data relating to the same sector and representing blade sensor data on other blades. When an event is detected in a given sector, an individual pitch contribution is determined in the sector, and the blades are then pitched according to this individual pitch contribution for that given sector at least partly during passage of the sector.

Abstract: A method and system for improving the balance of a rotor in a wind turbine, including; determining blade load data associated with a selected rotor blade pair; determining, based on the blade load data, pitch imbalance data associated with the selected rotor blade pair, wherein the pitch imbalance data associated with a rotor blade pair is based on measurements of at least blade loading, rotor speed and wind speed; and, determining and applying pitch control inputs to one or both of the selected rotor blade pair in order to reduce the severity of the rotor imbalance.

Abstract: The rotor blades of a wind turbine each have a plurality of fiber-optic pressure variation sensors which can detect the onset of a stall condition. The output of the stall condition sensors is input to a stall count circuit which increases a stall count signal each time a stall indication is received. The stall count signal is decayed exponentially over time and the current signal is summed with the decayed signal from a previous sampling period to form a value from which a stall margin is determined. An ?:? curve of tip speed to wind speed ratio ? against pitch angle reference ? is then determined from the stall margin.

Abstract: A wind turbine is controlled in response to an estimate of vertical and/or horizontal wind shear. A tilt moment is estimated from flapwise and edgewise blade bending moments, azimuth and blade pitch positions and used to estimate vertical wind shear. A yaw moment is also estimated from flapwise and edgewise blade bending moments, azimuth and pitch position and used to estimate horizontal wind shear. A tip speed ratio is determined from an estimate of wind velocity over the rotor plane and is used to set a blade pitch angle which is passed to a blade pitch controller. The pitching may be collective or individual. In the latter case, the tip speed ratio is determined from a plurality of rotor plane positions to derive a cyclic pitch reference for each blade.

Abstract: The rotor blades of a wind turbine each have a plurality of fibre-optic pressure variation sensors which can detect the onset of a stall condition. The output of the stall condition sensors is input to a stall count circuit which increases a stall count signal each time a stall indication is received. The stall count signal is decayed exponentially over time and the current signal is summed with the decayed signal from a previous sampling period to form a value from which a stall margin is determined. An ?:? curve of tip speed to wind speed ratio ? against pitch angle reference ? is then determined from the stall margin.

Abstract: The invention relates to a method of controlling a wind turbine comprising one or more blades attached to a rotor hub, the one or more blades being arranged to pitch relative to the hub, the method comprising the steps of obtaining a blade load signal comprising data on an absolute load on the one or more blades; processing the blade load data to detect a high thrust wind event, and generating a control signal comprising a pitch contribution for affecting the blades to pitch out of the wind in response to the detected wind event. The invention also relates to a wind turbine, a control system for a wind turbine and a computer program product being adapted to enable a computer system to perform the method of the invention.

Abstract: A method of controlling a wind turbine comprising blades attached to a rotor hub for rotation in a rotor plane and a control system for individually pitching the blades relative to the hub. The method comprises dividing the rotor plane into a number of sectors, determining the individual sectors for each blade during the rotation by means of an azimuth angle sensor, and obtaining blade sensor data from a blade sensor on an individual blade relating to a sector, and comparing the obtained data with data relating to the same sector and representing blade sensor data on other blades. When an event is detected in a given sector, an individual pitch contribution is determined in the sector, and the blades are then pitched according to this individual pitch contribution for that given sector at least partly during passage of the sector.

Abstract: Embodiments of the invention generally relate to wind turbine generators, and more specifically to improving power production in wind turbine generators. A rotor plane of the wind turbine may be divided into a plurality of sections. A characteristic of wind associated with each section may be determined. An optimal pitch angle may be determined for each section based on the associated wind characteristic. A pitch controller may adjust the pitch angle of a blade to the optimal pitch angle as the blade sweeps through the section.

Abstract: Blades of a wind turbine attached to a rotor hub for rotation in a rotor plane may be adjusted by a control system for individually pitching the blades relative to the hub. The rotor planes divided into a plurality of predefined section, wherein each section has an associated pitch reference value. A light detection and ranging device may be used to determine expected properties of wind in each respective section of the rotor plane so that the pitch reference value may be adjusted accordingly.

Abstract: Embodiments of the invention generally relate to controlling a wind turbine comprising blades attached to a rotor hub for rotation in a rotor plane and a control system for individually pitching the blades relative to the hub. The rotor planes divided into a plurality of predefined section, wherein each section has an associated pitch reference value. A light detection and ranging device may be used to determine expected properties of wind in each respective section of the rotor plane so that the pitch reference value may be adjusted accordingly.