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: 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: A wind turbine system is described comprising a plurality of wind turbine modules, each including a rotor, mounted to a support structure including a tower. In use, each rotor has an associated rotating unbalance that defines an unbalance vector. The wind turbine system includes control means configured to coordinate the rotational speeds of the plurality of rotors to attenuate oscillations of the support structure caused by the rotating unbalance of the rotors. Also described is a method of controlling such a wind turbine system. The method comprises coordinating the rotational speeds of the plurality of rotors to attenuate oscillations of the support structure caused by the rotating unbalance of the rotors.

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 a system used to estimate the presence of water on a sensor. A parameter maintains a wind sensor temperature. The parameter can be tracked and evaluated to indicate a likelihood of water on the sensor. Alternatively, or in combination with the above, the sensor is adjusted intentionally or deactivated and reactivated to track a parameter response which is then used to indicate a likelihood of water on the sensor.

Abstract: According to an embodiment of the present invention there is provided an apparatus for controlling a sub-system of a wind turbine. The apparatus comprises a cooling system comprising first and second heat exchangers, and a fluid circuit arranged to enable a coolant to flow between the first and second heat exchangers; and a processor. The processor is configured to: monitor one or more operational parameters of the cooling system; determine an icing risk based on the one or more operational parameters; and generate a control signal for output to the wind turbine sub-system in dependence on the determined icing risk.

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 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 invention relates to a method for determining dynamic parameters associated with damping properties of a wind turbine. The method involves active excitation of tower oscillations by adjusting the pitch or rotor torque. After the active excitation, the parameters can be determined from the passive decay of the excited oscillations. Alternatively, the oscillations can be actively damped, so that the parameters can be determined from the active decay of the excited oscillations. The method for promoting oscillations may be triggered in response to different events or in response to predetermined times for determining the actual dynamic parameters.

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.

Abstract: A wind turbine control system comprising a controller of a control mechanism of a wind turbine, wherein the controller implements a computerized real-time blade model to calculate operational parameters of the controller, and wherein the computerized real-time blade model receives as inputs a determined wind turbine operating point and a rotor-plane wind speed value that is estimated in real-time. In another aspect, the embodiments of the invention provide a method of controlling a control mechanism of a wind turbine. Advantageously, the invention provides a more flexible and responsive control system that is able to adapt to changing wind conditions even if those wind conditions are beyond what is usually predicted.

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 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: The invention relates to a wind turbine system (1) with several wind turbine modules (2) mounted to a support structure (3). A control system is configured to determine a lift command (21) for a particular wind turbine module (2?) of the 5 plurality of wind turbines modules (2). The control system is applying the lift command (21) to a corresponding rotor blade pitch adjustment system of the particular wind turbine module (2?) so as to create a lift force (F_up) in the opposite direction of gravity on the particular wind turbine module mounted on the support structure. Providing an upwards lift force on one, or more, particular 10 wind turbine module(s) may reduce, or eliminate, static and/or dynamical loads from the wind turbine module on the support structure.

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 of controlling a wind turbine is described. The method comprises calculating a current wear rate for each of the main bearing of a turbine rotor and the blade bearings of rotor blades mounted on the turbine rotor, and calculating a blade pitch adjustment of the rotor blades to achieved a desired ratio between main bearing wear and blade bearing wear in dependence on the calculated current wear rates of the main bearing and the blade bearings.

Abstract: There is presented a wind turbine system, wherein the wind turbine system is comprising a support structure, a plurality of wind turbine modules mounted to the support structure wherein each of the plurality of wind turbine modules comprises a rotor, and wherein the wind turbine system further comprises a control system, wherein the control is arranged to execute a wind turbine system transition from a first system operational state of the wind turbine system to a second system operational state of the wind turbine system, and wherein the wind turbine system transition is performed by executing a plurality of wind turbine module transitions from a first module operational state of a wind turbine module to a second module operational state of the wind turbine module wherein the plurality of wind turbine module transitions are distributed in time with respect to each other.

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 wind turbine system is described comprising a plurality of wind turbine modules, each including a rotor, mounted to a support structure including a tower. In use, each rotor has an associated rotating unbalance that defines an unbalance vector. The wind turbine system includes control means configured to coordinate the rotational speeds of the plurality of rotors to attenuate oscillations of the support structure caused by the rotating unbalance of the rotors. Also described is a method of controlling such a wind turbine system. The method comprises coordinating the rotational speeds of the plurality of rotors to attenuate oscillations of the support structure caused by the rotating unbalance of the rotors.

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.