Vestas Wind Systems A/s

Senvion Gmbh

Thomas Krüger

Fabio Caponetti

Jesper Sandberg Thomsen

Jacob Deleuran Grunnet

Ian Couchman

Ali Zaib

Martin Atzler

Martin Brødsgaard

Jorge Martinez Garcia

Martin Ansbjerg Kjær

Keld Hammerum

Lars Finn Sloth Larsen

Robert Bowyer

Poul Brandt Christensen

Stefan Schrader

Thomas Scheel

Per Brath

Carsten Nørlund Thomsen

Ilias Konstantinos Ariston

Peter Mortensen Sigfred

Martin BrØdsgaard

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.

Control of a wind turbine using real-time blade model

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.

Control of a wind turbine using real-time gain calculation

The invention relates to a control apparatus and method for controlling the rotor blades of a wind turbine, and in particular to controlling the rotor blades during an extreme wind event. An extended mode of operation of the wind turbine rotor beyond the cut-out wind speed is provided. In the extended mode of operation, the pitch of the wind turbine blades is actively controlled so that the rotor and the generator idle at a designated rotational speed. The rotational speed may be relatively high, say 15 to 20% of the nominal speed, compared with minimal speeds experienced by purely feathered wind turbine blades, and may be further controlled as a function of the incident wind speed. Output power control in the extended mode may be zero but is preferably a low, but non-zero value. The output power so produced may then be used as an auxiliary power source for controlling the wind turbine in situations where the utility grid fails.

Rotor blade control for high winds

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. In various embodiments the parameters characterising the oscillation or loads of the tower comprise current oscillations and their amplitude, an estimate of loads incurred in the turbine structure, an estimate whether damping in the near future might become necessary, an indication whether a different oscillation damping algorithm than individual blade pitch control is currently performing, and an indication whether a wind speed is above a certain portion of a rated wind speed.

Selective wind turbine damping using active damping system

The invention presents a method for operating a horizontal axis wind turbine, the wind turbine comprising a tower and a rotor with at least one rotor blade, the rotor being connected to the tower, and being adapted to drive a generator connected to a utility grid, wherein a pitch angle of each rotor blade is adjustable, the method comprising detecting, when the wind turbine is in an idling power producing situation in relation to the utility grid, a tower oscillation, and controlling, when the wind turbine is in the idling power producing situation, the pitch angle of the at least one rotor blade so as to produce aerodynamic forces counteracting the detected tower oscillation.

Counteracting tower oscillations of an idling wind turbine

Methods and systems for controlling a wind turbine in a manner that takes into account the degree of loading of and damage to one or more components of the turbine are provided. An operational load on a wind turbine part is determined, and is used to compute a damage signal. The damage signal is indicative of the potential damage to the component or to the turbine as a whole that will result if action is not taken to reduce or mitigate the determined load. When the damage signal exceeds a pre-determined threshold, load-reducing wind turbine control means are activated to obviate the estimated damage.

Methods and apparatus for controlling wind turbines

A wind turbine comprising a tower, a rotor including a plurality of blades, an electrical generator operatively coupled to the rotor, and a control system including an active damping module configured to monitor oscillatory motion of the wind turbine and to output a damping demand signal to damp the oscillatory motion. The control system is configured to perform a rotor imbalance determination process including: controlling the rotating frequency of the rotor so that it substantially coincides with the natural frequency of the tower, determining rotor imbalance data based on the damping demand signal and evaluating said rotor imbalance data to determine the presence of a rotor imbalance condition, and correcting the rotor imbalance condition by applying pitch control inputs to one or more of the plurality of blades so as to reduce the severity of the rotor imbalance. The invention may also be expressed as a method.

Improvements relating to the determination of rotor imbalances in a wind turbine

A fast-converging and reliable method for estimating a wind speed at, for example, a wind turbine comprising a rotor carrying a set of variable pitch angle wind turbine blades. The estimated wind speed is iteratively derived using a wind turbine rotor rotational speed, a turbine blade pitch angle, and a derived initial estimated wind speed. The initial estimated wind speed is based on the rotational speed and an initial tip speed ratio. The initial tip speed ratio is selected to be a value greater than a minimum tip speed ratio, wherein the minimum tip speed ratio defines a control region stability limit as a function of the pitch angle. Thus, for a given pitch angle, a minimum tip speed ratio is derived as a limit or boundary point between a stable control region and an unstable control region.

Method for estimating a wind speed at a wind turbine

The invention relates to a method for wind turbine generators for reducing electrical disturbances in the form of power variations which are caused by damping controllers arranged the compensate structural oscillations by inducing shaft torque variations. The shaft torque variations are generated by imposing corresponding variations in a generator set-point, e.g. a power or torque set-point. Variations in the generator set-point cause undesired variations in the power injected to the grid by one or more wind turbine generators. According to an embodiment of the invention the electrical disturbances may be reduced by limiting a damping controller's control action. The amount of limitation or restriction of the damping controller may be determined on basis on electrical disturbance information determined from power measured e.g. at a location on the grid.

Control system for wind turbines for reducing disturbances in an electrical grid

A method of operating a wind turbine is provided. The wind turbine comprises a turbine rotor with at least two blades, each blade having a variable pitch angle. The method comprises determining mechanical loads on the blades, determining an asymmetric load moment experienced by the turbine rotor based on the mechanical loads on the blades, determining high order harmonics from the asymmetric load moment, and determining an individual pitch control signal for each of the blades for varying the pitch angle of each blade to compensate for the asymmetric load moment. The individual pitch control signal for each blade is determined at least based on the high order harmonics.

Compensation for asymmetric load moment experienced by wind turbine rotor

A method for controlling an individually pitched wind turbine during shutdown is disclosed, the wind turbine comprising at least three wind turbine blades (). In response to a shutdown command for stopping operation of the wind turbine, a blade parameter of each of the wind turbine blades (), e.g. pitch angle, bending moment or blade acceleration, is determined. The blade parameters of the wind turbine blades () are compared, and a shutdown strategy for the wind turbine is selected from a group of two or more predefined shutdown strategies, based on the comparing step. Finally, the wind turbine blades () are moved towards a feathered position in accordance with the selected shutdown strategy.

Method for controlling a wind turbine during shutdown

The present invention relates to a method for regulating a flow of power between a wind power facility and a power grid connected thereto. The method comprises the steps of determining whether power is to be delivered to or absorbed from the power grid, and at least partly disabling or at least partly enabling one or more power consuming auxiliary systems in response to said determination. Moreover, an arrangement for delivering additional power to a power grid is provided.

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Tilst, Denmark

Thomas Krüger