Method for operating a pitch-controlled wind turbine
AssigneeNordex Energy GmbH
InventorsWolfgang Kabatzke, Hermann Rochholz, Jochen Birkemeyer
Life of this patent
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Abstract
Method for operating a pitch-controlled wind turbine, in which a set-point value for the generator torque (M) is prescribed in dependence upon a rotational speed (n) of the generator or of the rotor. A transition point (n3, M3) is provided at which a transition from a partial-load operation to a nominal-load operation occurs. A control of the rotational speed takes place by adjusting the blade pitch angle for a set-point value (M3) from the transition point. The values (n3, M3) of the transition point are determined in dependence upon a current value of the air density. With falling air density, the rotational speed (n3) is increased and/or the set-point value for the generator torque (M3) is reduced.
Claims8
A method for operating a pitch-controlled wind turbine having a rotor blade, a rotor and a generator, the method comprising the steps of:
- prescribing a set-point value for the generator torque (M) in dependence upon a rotational speed (n) of the generator or of the rotor;
- providing a transition point (n3, M3) whereat a transition occurs from a partial-load operation into a nominal-load operation wherein said rotational speed (n) is controlled by adjusting the pitch angle of said rotor blade;
- determining the values (n3, M3) of said transition point in dependence upon a current value of the air density (ρ);
- with falling air density, increasing the rotational speed (n3) and/or reducing said set-point value (M3) for the generator torque;
- determining a change (Δρ) in said air density (ρ) and comparing said change (Δρ) to a maximum allowable change (Δρ2) in air density;
- and,
- if said change (Δρ) in air density (ρ) exceeds said maximum allowable change (Δρ2), then changing said transition point.
Dependencies are inferred from the claim text.