Wind Turbine Noise Reduction Techniques

A method for predicting tonal noise produced by wind turbines. The method involves acquiring vibration data from sensors on a wind turbine drivetrain during testing in a rig and correlating it with tonal noise data to find vibrations associated with tonal noise. This relationship is then used to predict tonal noise from vibration data during normal wind turbine operation.

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Identifying operating parameters of a wind turbine that contribute to the generation of tonal noise. The method involves acquiring operating parameter data associated with a wind turbine and noise data synchronized with the operating parameter data. The noise data is binned based on values of one parameter, such as generator RPM, and analyzed within each bin based on values of a second parameter, like pitch or power. The analysis finds correlations between parameter values and tonal noise levels, identifying critical parameter ranges that cause tonal noise. This allows adjusting turbine operation to avoid those ranges and reduce tonal noise.

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A wind turbine rotor blade with an integrated noise reduction device to reduce trailing edge noise. The device is a porous cover that attaches to the blade within the boundary layer. It spans over part of the blade surface at a small distance away. This modification moves large turbulent structures away from the blade surface, reducing surface pressures and noise radiation. The porous cover allows airflow through.

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Disk brake for wind turbine azimuth drives that reduces noise by providing cleaning channels to remove brake dust. The channels allow cleaning brushes or other tools to access the brake disk ring area between the brake pads. This prevents brake dust build-up which can cause noise and reduced braking performance.

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A wind turbine generator with reduced noise and vibration versus conventional designs. The generator has a stator with a split iron core made of modules, and a single-layer winding using a special tooth slot configuration. The tooth slots are designed to reduce the fifth and seventh harmonic magnetic fields, which cause torque ripple and vibration. The stator iron core is split to allow easier manufacturing and transportation of large wind turbine generators.

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Airfoil design to reduce trailing edge noise from wind turbine blades and other applications like aircraft wings. The airfoil has elongated noise-reducing features on the pressure and/or suction sides. These features can be ridges or fins extending upstream from the trailing edge. They break up spanwise-oriented turbulence approaching the trailing edge, deflect turbulence away from the edge, and create vortices or waves that reduce turbulence-edge interaction. The features reduce trailing edge noise by modifying the boundary layer turbulence as it nears the edge.

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Noise reducing airfoil for wind turbines and other applications. The airfoil has a treatment on the pressure and/or suction sides near the trailing edge to modify the boundary layer turbulence and reduce spanwise correlation approaching the trailing edge. This treatment breaks up turbulence, deflects it away from the edge, and creates spanwise vortices or instability waves that reduce the turbulence-edge interaction. The treatment consists of thin members placed upstream of the trailing edge like rails or fins.

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Reducing noise from wind turbine blades allows turbines to operate at maximum efficiency without being put into noise-reduced operation mode. The noise is reduced by retrofitting existing wind turbine blades with a serrated trailing edge made from acoustically absorbent materials. The serrations reduce coherent scattering of noise sources to mitigate overall noise levels. The absorbent materials further reduce noise by damping turbulence and absorbing sound.

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Rotor blade for wind turbines with reduced noise generation from the trailing edge. The blade has serrations along part of the trailing edge, with the spaces between the teeth filled with a porous material like foam or fibers. This reduces noise compared to a smooth trailing edge by modifying the airflow and preventing turbulence. The porous material in the serrations acts as a buffer to dampen the turbulent flow that causes noise.

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A serrated trailing edge panel for wind turbine blades that reduces noise during operation. The serrated panel attaches to the trailing edge of a wind turbine blade to form serrations. Its base part attaches to the blade, and serrations extend from the base. The serrated panel is designed to optimize noise reduction by having a corrugated exterior surface between the serrations that aligns with the serration bases, as well as rounded connecting surfaces between the serrations.

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Wind turbine rotor blade design to reduce noise generated at the trailing edge section. The blade has serrations along the trailing edge with gaps filled by parallel comb elements. This reduces noise compared to conventional blades. The blade also has ridges that manipulate airflow along the blade surface.

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Wind turbine rotor blade with serrated trailing edge that reduces noise and improves lift compared to prior art serrated trailing edges. The serrations have unequal length edges and the bisectors are angled between 70-110 degrees from the trailing edge tangent.

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A method for damping edgewise vibrations in wind turbine rotor blades by measuring blade motion parameters and pitching the blades to counteract vibrations. The method involves individually measuring the edgewise vibration velocity of each blade using sensors on the blades. If the vibration exceeds a threshold, a pitch control signal is generated to pitch the blade in a manner proportional to the vibration velocity. This emulates a viscous damper to counteract the vibration. The blade pitch offset is in addition to normal pitch control.

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This method involves dampening edgewise vibrations of wind turbine blades to prevent damage. It detects the blade vibrations using a sensor, generates a blade pitch control signal based on the vibration measurement, and adjusts the blade pitch angle to dampen the vibrations.

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A method to dampen vibrations in wind turbines in a wind farm to prevent power oscillations at the grid connection point. The method involves measuring vibrations in each turbine and determining damping control signals to counteract them. The control signals are then selectively applied to some turbines, such that the combined signals sum below a threshold. This allows damping of specific turbine vibrations without over-damping the whole farm. It avoids the issue of synchronized tower oscillations causing power oscillations at the grid connection point.

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