Methods and apparatus for operating a wind turbine

Abstract

A method for operating a wind turbine having at least one blade includes determining an ambient air operating envelope and controlling a power output of the wind turbine at least partially based on the determined ambient air operating envelope. Determining an ambient air operating envelope includes measuring at least one of an ambient air temperature, an ambient air pressure, an ambient air humidity, and wind turbine power output. The method also includes comparing at least one of a measured ambient air temperature, a measured ambient air humidity and a measured ambient air pressure to predetermined ambient air temperature, pressure and humidity values. The method further includes referencing the predetermined ambient air temperature, pressure and humidity values to at least one operational parameter of the wind turbine. The method also includes determining if an existing wind turbine power output is within a range associated with the determined ambient air operating envelope.

Description

BACKGROUND OF THE INVENTION[0001]This invention relates generally to wind turbines, and more specifically to methods and apparatus for controlling operation of a wind turbine.[0002]Generally, a wind turbine includes a rotor having multiple blades. The rotor is sometimes mounted within a housing, or nacelle, that is positioned on top of a base, for example a truss or tubular tower. At least some known electric utility grade wind turbines (i.e., wind turbines designed to provide electrical power to an electric utility grid) can have rotors of 30 meters (m) (98 feet (ft)) or more in diameter. The rotor blades transform mechanical wind energy into a mechanical rotational torque that drives one or more generators. The generators are sometimes, but not always, rotationally coupled to the rotor through a gearbox. The gearbox steps up the inherently low rotational speed of the turbine rotor for the generator to efficiently convert the rotational mechanical energy to electrical energy, which...

AI Technical Summary

Benefits of technology

[0005]In one aspect, a method for operating a wind turbine. The method includes measuring an ambient air temperature and decreasing a power output of the wind turbine if the measured ambient air temperature is below a predetermined limit to thereby facilitate reducing loads acting on components of the wind turbine.

Problems solved by technology

Operation of a wind turbine below this temperature range may require new load calculations which will exceed the design load envelope if no countermeasures are taken, possibly resulting in the need of new, reinforced components.

At least some known wind turbines, when subjected to cold weather conditions with ambient air temperature values below the lower temperature limit of the allowable temperature range, are shut off, which is disadvantageous insofar as no electric output power is generated.

Such stalling reduces a potential electric power output of the wind turbine.

Moreover, reestablishment of airflow around at least some known wind turbine rotor blades after stalling may cause a short-term increase in generator speed and / or electric power output that may be difficult for a controller of the wind turbine to process.

Such controller processing difficulty may increase a probability of the wind turbine to be disconnected from an electric grid due to over-speed and / or over-production conditions.

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