Adjusting a rotor blade pitch angle
AssigneeSiemens Aktiengesellschaft
InventorPeder Bay Enevoldsen
Life of this patent
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Abstract
A method of adjusting a pitch angle of a rotor blade of a rotor of a wind turbine is provided. The method comprises varying the pitch angle of the rotor blade during wind operation of the wind turbine from a starting angle to reach a limit angle (α1, α2) at which the rotor blade and/or an operational value (P) of the wind turbine reaches a predefined threshold limit (P1/2; α1, α2), deriving a safe angle (α3, α4) dependent on the limit angle (α1, α2), operating the rotor blade at the safe angle (α3, α4) or an angle from the safe angle (α3, α4) away from the limit angle (α1, α2). A pitch angle adjustment system is also provided for the same purpose.
Claims15
A method of adjusting a pitch angle (α) of a rotor blade of a rotor of a wind turbine, comprising:
- a) varying the pitch angle of the rotor blade during power-generating operation of the wind turbine from a starting angle to reach a limit angle applicable to current boundary conditions, the limit angle comprising a stall angle (α1, α2), wherein the varying of the pitch angle is effective to ensure the rotor blade starts to stall,
- b) deriving a safe angle (α3, α4) dependent on the stall angle (α1, α2),
- c) operating the rotor blade at the safe angle (α3, α4) or an angle lower than the safe angle (α3, α4) during power-generating operation and for a period of time,
- d) repeating steps a, b, and c together to ensure the respective limit angle reflects respective current boundary conditions at different points in time during power-generating operation, and
- reducing a rotational speed of the rotor to below a speed limit before varying the pitch angle.
A method of adjusting a pitch angle (α) of a rotor blade of a rotor of a wind turbine, comprising:
- a) operating the rotor blade at a predetermined maximum permissible angle during power-generating operation of the wind turbine,
- b) varying the pitch angle of the rotor blade during wind operation of the wind turbine from the predetermined maximum permissible angle in order to reach a limit angle at which a power output reaches a maximum power output or a limit angle at which the rotor blade starts to stall,
- c) deriving a safe angle (α3, α4) dependent on the limit angle (α1, α2),
- d) operating the rotor blade at the safe angle (α3, α4) or an angle lower than the safe angle (α3, α4), and
- reducing a rotational speed of the rotor to below a speed limit before varying the pitch angle.
Dependencies are inferred from the claim text.