Method and apparatus for producing wind energy with reduced wind turbine noise

Abstract

A method for controlling noise from a wind park that has a plurality of wind turbines includes monitoring noise emission from the wind turbines in at least a near field area and utilizing a transfer function of noise emission to determine a noise impact importance of the wind turbines at one or more locations in a far field area beyond a boundary of the wind park. The method further includes determining which, if any, wind turbines to operate in a noise-reduced operation mode in accordance with the noise impact importance determination and controlling operation modes of the wind turbines in accordance with the determination of which, if any, wind turbines to operate in a noise reduced mode.

Description

BACKGROUND OF THE INVENTION [0001] This invention relates generally to power generation systems and more particularly to methods and apparatus for reducing noise impact from wind turbine installations. [0002] In many parts of the world, the issuance of permits for wind turbine installations is based upon the environmental noise impact effected or potentially effected by the installation. For example, in most European countries, a maximum (fixed) sound pressure level is set by type of land area (agricultural, industrial, residential, or other) in the vicinity of wind turbine park boundaries, or in some noise regulation cases, the approach of industrial noise relative emergence is favored. Noise emergence is defined herein as the relative noise level increase related to an industrial installation with reference to the initial, existing background noise level. [0003] At least three known methods exist for controlling noise from wind turbine installations. In a first known method descri...

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Benefits of technology

[0006] In one aspect, the present invention therefore provides a method for controlling noise from a wind park that includes a plurality of wind turbines. The method includes monitoring noise emission from the wind turbines in at least a near field area and utilizing a transfer function of noise emission to determine a noise impact importance of the wind turbines at one or more locations in a far field area beyond a boundary of the wind park. The method further includes determining which, if any, wind turbines to operate in a noise-reduced operation mode in accordance with the noise impact importance determination and controlling operation modes of the wind turbines in accordance with the determination of which, if any, wind turbines to operate in a noise reduced mode.

[0007] In another aspect, the present invention provides an apparatus for reducing noise impact from a wind park having a plurality of wind turbines. The apparatus includes at least one site reference microphone and a plurality of site boundary area microphones, and a computer configured to monitor noise emission from the wind turbines utilizing the site reference microphone(s) and the plurality of site boundary microphones. The computer is further configured to utilize a transfer function of noise emission to determine a noise impact importance of the wind turbines at one or more locations in the far field beyond a bounda

Problems solved by technology

However, this method may not necessarily lead to proper turbine noise reduction because wind turbine rotor noise exhibits sound directivity not necessarily maximum in down-wind direction.

Thus, wind direction statistics may not adequately address relevant noise contributions.

This method may lead to dramatic energy capture loss as atmospheric propagation effects above mentioned (air temperature gradient, wind gradient, and site topography) are not taken into account.

Moreover, a fixed basic acoustic model does not dynamically adapt to changing site background acoustic conditions.

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