Method of reducing a structural unbalance in a wind turbine rotor and device for performing the method
AssigneeSiemens Aktiengesellschaft
InventorPer Egedal
Life of this patent
Estimating the term…
Abstract
Disclosed is a method of reducing a structural unbalance in a wind turbine rotor with pitch control and a control device for performing the method are provided. The method comprises the steps of: detecting a magnitude of the structural unbalance and its phase in relation the rotor's azimuth (θ) on the basis of a measurement of the rotor's azimuth (θ) and a measurement of the rotor speed or the generator speed (ω), establishing individual pitch angle offsets for each blade of the rotor on the basis of the magnitude and the phase, and adding the individual pitch angle offsets to the respective pitch angles of the blades of the rotor.
Claims3
A control device for proving pitch angle offsets for each blade of a wind turbine rotor so as to reduce a structural unbalance in the rotor, comprising:
- a rotor speed detector designed to output a rotor speed signal representing the detected rotor speed;
- a rotor azimuth detector which is designed to output a rotor azimuth signal representing the detected rotor azimuth;
- an oscillation detecting unit connected to the rotor speed detector and the rotor azimuth detector for receiving the rotor speed signal and the rotor azimuth signal, respectively, which is designed to detect a frequency component resulting from a structural unbalance in the wind turbine rotor on the basis of the rotor speed signal and the rotor azimuth signal, and which is designed to output a frequency component signal representing the frequency component detected in the oscillation detecting unit;
- and
- a calculation unit connected to the oscillation detecting unit that receives the frequency component signal and designed to calculate individual pitch angle offsets for each blade of the wind turbine rotor on the basis of the frequency component signal such that the frequency component detected in the oscillation detecting unit is reduced,
- wherein the calculation unit comprises:
- a correction factor calculator unit connected to the oscillation detecting unit for receiving the frequency component signal and designed to calculate and to output a complex correction factor on the basis of the frequency component signal, and
- a multiplier which is connected to the oscillation detecting unit for receiving the frequency component signal and to the correction factor calculator unit for receiving the complex correction factor and designed to multiply the frequency component signal by the complex correction factor.
Dependencies are inferred from the claim text.