Abstract: A method for damping an oscillation of a tower of a wind turbine is disclosed, wherein a pitch angle of each of the one or more rotor blades is individually adjustable, the method comprising damping the oscillation of the tower by pitching each rotor blade individually according to tower damping pitch control signals, wherein each tower damping pitch control signal comprises a first periodic component, where a first frequency of the first periodic component corresponds to a frequency difference between a tower frequency of the oscillation of the tower and a rotor frequency of a rotation of the rotor, and where a second periodic component has been reduced or removed. A second frequency of the second periodic component corresponds to a frequency sum of the tower frequency and the rotor frequency.

Abstract: A method and associated control arrangement are disclosed for controlling a power output of a wind power plant (WPP) according to a predetermined power ramp rate limit, the WPP comprising a plurality of wind turbine generators (WTGs). The method comprises receiving a first signal indicating that a first WTG is in a ready state to begin producing power. The method further comprises, upon determining that, responsive to the received first signal, beginning power production of the first WTG at a predetermined default power ramp rate would cause the power output of the WPP to exceed the power ramp rate limit, controlling power production of the first WTG using at least one of: a first delay, a power ramp rate reference less than the default power ramp rate, and a power reference less than a nominal power output of the first WTG.

Abstract: A method for controlling a wind turbine is disclosed, the wind turbine comprising a set of wind turbine blades (1), each wind turbine blade (1) being provided with at least one air deflector (2) being movable between an activated position in which it protrudes from a surface of the wind turbine blade (1) and a de-activated position. The occurrence of an event causing a change in operational conditions is registered, and a new operating state for the wind turbine is determined, the new operating state meeting requirements of the changed operational conditions. The air deflectors (2) of the wind turbine blades (1) and pitch angles of the wind turbines blades (1) are controlled in order to reach the new operating state for the wind turbine, and in such a manner that the control of the pitch angles of the wind turbine blades (1) is performed while taking information regarding the control of the air deflectors (2) into account.

Abstract: A method for operating a renewable energy power plant comprising a plurality of renewable energy generators. The method comprises: identifying a predetermined condition of the renewable energy power plant, of the grid, or of the connection between the renewable energy power plant and the grid, the predetermined condition indicating a weak grid interconnection between the renewable energy power plant and the grid; and controlling each renewable energy generator in an adaptive active power mode in response to recovery of the grid from a voltage deviation. The adaptive active power mode comprises: determining a thermal capacity of a chopper resistor of the renewable energy generator; calculating, based upon the determined thermal capacity, a limit level of rate of change of active power output that may be implemented by the renewable energy generator; and operating the renewable energy generator to output active power at the calculated rate of change limit level.

Abstract: A wind turbine control system comprising at least one control module configured to output a control signal for a control mechanism of a wind turbine, and a gain calculator for calculating a gain parameter associated with the control module, wherein the gain parameter is calculated based on a computerized real-time blade model using a determined wind turbine operating point as an input. The blade model may be a blade element momentum model. In another aspect, the invention may be expressed as a method of controlling a control mechanism of a wind turbine.

Abstract: A method for operating a renewable energy power plant comprising a plurality of renewable energy generators. The method comprises: identifying a predetermined condition of the renewable energy power plant, of the grid, or of the connection between the renewable energy power plant and the grid, the predetermined condition indicating a weak grid interconnection between the renewable energy power plant and the grid; and controlling each renewable energy generator in an adaptive active power mode in response to recovery of the grid from a voltage deviation. The adaptive active power mode comprises: determining a thermal capacity of a chopper resistor of the renewable energy generator; calculating, based upon the determined thermal capacity, a limit level of rate of change of active power output that may be implemented by the renewable energy generator; and operating the renewable energy generator to output active power at the calculated rate of change limit level.

Abstract: There is presented a method for controlling a plurality of wind turbines comprising measuring wind turbine operation parameters in a model relating a plurality of wind turbine parameters to each other, estimating one wind turbine operation parameter value based on the model and the measured remaining wind turbine operation parameter values, providing a reliability parameter value for each wind turbine based on a difference value, said difference value being a difference between the estimated wind turbine operation parameter value, and the measured wind turbine operation parameter value corresponding to the wind turbine operation parameter for which the estimated wind turbine operation parameter value is provided, and controlling the plurality of wind turbines based on the corresponding plurality of reliability parameter values.

Abstract: A method of controlling a wind turbine is provided. The method comprises providing a primary power reference signal and a secondary power reference signal. The primary power reference signal is limited according to a primary signal limit. The secondary power reference signal is limited according to a secondary signal limit. The primary power reference signal and the secondary power reference signal are combined to provide a combined power reference signal, which is provided to a power or torque control system of the wind turbine.

Abstract: Embodiments are generally directed to techniques for operating a wind turbine of a wind power plant. An associated method comprises determining, using one or more sensors of the wind turbine, a first power production level of the wind turbine; determining, during an unconstrained operation of the wind turbine, one or more available power correction factors using the first power production level; determining, using one or more wind power parameters applied to a predefined model for estimating an available power of the wind turbine, an estimated available power value; adjusting the estimated available power value using the one or more available power correction factors to produce the available power value; and controlling, using the available power value, the wind turbine to produce a second power production level.

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: The present invention refers to a method for operating a wind turbine, the wind turbine particularly comprising a tower and a rotor with rotor blades. The pitch angles of the rotor blades are adjusted to generate a force on the rotor and the tower. The force is adjusted to counteract and damp an oscillation. The adjustment is enabled by an activation decision unit, if the activation decision unit decides that certain parameters characterising the oscillation or loads of the tower indicate a requirement and/or if the activation decision unit determines that the generated force is sufficient to counteract an oscillation of the tower.

Abstract: Embodiments of the present disclosure generally relate to apparatus and methods for preventing power dips associated with power ramping in wind turbines. One embodiment of the present disclosure provides a method for stabilizing power output in a wind turbine, which includes tracking a rate of change in an external reference, such as an external power reference or external torque reference, computing a feed-forward pitch angle adjustment according to the rate of change in the external power reference, and sending the feed-forward pitch angle adjustment to the wind turbine to adjust a pitch angle of rotor blades simultaneously with adjusting power output according to the external reference.

Abstract: The present invention relates to control of a wind turbine where nacelle vibration is reduced by use of blade pitching. The nacelle vibrations are reduced based on a position signal of the nacelle. A pitch signal is determined based on the position signal and applied to the pitch-adjustable rotor blades in order to reduce nacelle vibration.

Abstract: The control of the power output of wind turbine generator that operates in a derated mode to generate a produced power output level lower than an available power level. A pitch system sets the blade pitch of a rotor to a pitch value based on the received power reference signal. A power system controls the produced power output level of the wind turbine to the requested power output level. Moreover, the blade pitch of the rotor is further controlled by a pitch feedback control loop that modifies the pitch value based on a difference between the produced power output level and the requested power output level.

Abstract: A method for controlling a wind turbine is disclosed, the wind turbine comprising a set of wind turbine blades (1), each wind turbine blade (1) being provided with at least one air deflector (2) being movable between an activated position in which it protrudes from a surface of the wind turbine blade (1) and a de-activated position. The occurrence of an event causing a change in operational conditions is registered, and a new operating state for the wind turbine is determined, the new operating state meeting requirements of the changed operational conditions. The air deflectors (2) of the wind turbine blades (1) and pitch angles of the wind turbines blades (1) are controlled in order to reach the new operating state for the wind turbine, and in such a manner that the control of the pitch angles of the wind turbine blades (1) is performed while taking information regarding the control of the air deflectors (2) into account.

Abstract: Embodiments herein describe varying the rotor speed based on the current wind speed when operating in a low power mode. Generally, as the wind speed increases above the rated wind speed (i.e., the wind speed at which the turbine is capable of producing its rated or maximum output power), the rotor speed can be reduced thereby minimizing the risk that the turbine experiences smearing or torque reversals. In one embodiment, as the rotor speed decreases, the turbine maintains the ability to ramp to the rated power of the turbine only by pitching in the blades to an optimal blade pitch angle. Thus, upon receiving a request to cease operating in the low power mode, the turbine can increase the output power to the rated power without first increasing the rotor speed.

Abstract: The present disclosure relates to a control system for a wind turbine comprising more controllers and where at least some of the controllers operate at different sample frequencies. The control system comprises at least two controller units, a first controller (10) for determining an operational value (OV) of a sub-system and a second controller (20) for the sub-system. The second controller operates at a higher sample frequency than the first controller. It is disclosed that a faster reaction to a received demand value (V1), received for controlling the sub-system, can be obtained by setting the operational value (OV) of the sub-system as the sum of an internal operational value (V5) and a difference value (V4).

Abstract: The present invention relates to a method for controlling a wind turbine, the wind turbine comprises a rotor connected to a generator, and a rotational speed controller configured to control a speed of the rotor in response to a generator speed reference, and a power controller to control an electric power production, the method comprises the step for receiving a boost command to request a power boost event, so to increase the electrical power production, and imposing a dead band with a dead zone value limit to the rotational speed controller, and wherein the dead band imposes a zero signal to be send to the rotational speed controller, when a speed error is within the dead zone value limit and wherein the dead band imposes an error signal to be send to the rotational speed controller, when a speed error is greater than the dead zone value limit, the error signal being a function of the speed error and the dead zone value limit.

Abstract: A wind turbine system comprising a nacelle mounted on a tower, a rotor having a plurality of blades and a boundary layer control system configured to control airflow through blade surface openings in each of the blades. The wind turbine system includes a control system configured to perform at least one of the following: to monitor an operational speed parameter of the wind turbine, and to activate the boundary layer control system if it is determined that the 1 operational speed parameter exceeds a predetermined speed parameter threshold; to monitor tower motion and to activate the boundary layer control system based on a determination of excessive tower motion; to monitor for a wind turbine shutdown condition, and to activate the boundary layer control system if it is determined that a wind turbine shutdown condition has been identified; and to monitor the aerodynamic loads on the blades, and to activate the boundary layer control system also based on a determination of excessive blade loads.

Abstract: The invention relates to a method for controlling a wind turbine in partial and full load. In order to avoid disadvantages of switching between partial and full load controllers, the wind turbine control system is configured so that both the partial and full load controller provides control action during partial and full load. For that purpose, the partial and full load controllers are configured with variable gains, wherein gain scheduling is performed so that the gain of partial load controller is larger than the gain of the full load controller during partial load and vice verso so that the gain of the full load controller is larger than the gain of the partial load controller during full load.