US 7,445,431 B2Granted

Method of controlling aerodynamic load of a wind turbine based on local blade flow measurement

AssigneeForskningscenter Riso

InventorsTorben Juul Larsen, Helge Aagaard Madsen, Kenneth Thomsen

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Abstract

The present invention relates to a method of controlling the aerodynamic load of a wind turbine's blades individually in such a way that the dynamic aerodynamic loads on the turbine are reduced and power production is optimised. In general the present invention will improve the overall stability of the turbine leading to reduce fatigue loads, reduced extreme loads during operation and reduced risk of blade-tower interaction. In particular preferred embodiment of the invention, flow properties are measured locally on the different blades or in front of the blades and from these measurements the pitch angle settings are changed, in other ways changing the aerodynamic properties, for the blades through a control unit.

Claims14

Dependent claims

A method for controlling individually the operational condition of each blade of a wind turbine comprising one or more blades, said method comprising the steps of determining at least one aerodynamic flow property in the vicinity of each blade and determining based on the determined at least one aerodynamic flow property one or more operational conditions for each blade, wherein the one or more operational conditions comprises a pitch angle,

i) wherein said pitch angle comprises a contribution determined based on the angle of attack for the blade and a contribution determined based on a wind velocity relative to the blade,
ii) and wherein the contribution determined based on the angle of attack is determined based on a determined error between the instant angle of attack of the blade and the average angle of attack for all blades.

Dependencies are inferred from the claim text.

Facts

Application: 10/546,186Filed 18 Feb 2004
Priority: DK 2003 0024918 Feb 2003
Published: US 2006/0145483 A16 Jul 2006
Granted: 4 Nov 2008
Term ends: Not estimatedThe source records don’t support an estimate.

Classification15 codes

F03D 7/042
Automatic control; Regulation: by means of an electrical or electronic controller
F03D 7/022
The wind motors having rotation axis substantially parallel to the air flow entering the rotor: adjusting aerodynamic properties of the blades
F03D 7/0224
Adjusting aerodynamic properties of the blades: adjusting blade pitch
F03D 7/0232
Adjusting aerodynamic properties of the blades: with flaps or slats