Patent ID: 8021110
Filing Date: 2011-09-20
Classification: F03D,F05B,Y02E

Abstract:
1. A system for the noise reduction of wind turbines, comprising: an acoustic sensor attached to a wind turbine for providing a sensor signal, a detection unit, and a control unit, wherein said detection unit is configured to receive the sensor signal from said sensor and to detect a tonal component in said sensor signal, wherein the detection unit is further configured to compare an amplitude of the tonal component of the sensor signal at a frequency in a predetermined frequency channel to a threshold value for the frequency and generate a control input if the amplitude exceeds the threshold value, and wherein said control unit is configured to receive the control input from said detection unit, determine a current operating condition of the wind turbine, increase a rotational speed of a rotor of the wind turbine until an amplitude of the tonal component of the sensor signal at a hider frequency in a neighboring frequency channel is detected, compare the amplitude of the tonal component of the sensor signal at the higher frequency in the neighboring frequency channel to a predetermined threshold value for the higher frequency, and increase a generator torque of the wind turbine at the increased rotational speed of the rotor if the amplitude is less than the predetermined threshold value for the higher frequency.