MW Wind Turbine Noise Measurement and Assessment of Low-Frequency Tonal Noise

1.5 MW wind turbine noise was measured and its noise data was analyzed in accordance with IEC 61400-11:ed3(2012-11). For measurement of wind turbine noise, turbine operational signal such as generated electric power, wind speed at hub height and blade rotational speed are required. A mobile mast consisting of sensors with temperature, humidity, air pressure, wind speed and wind direction was used. All signal data are measured and recorded synchronized with time. Two additional measurement positions were selected for the analysis on the characteristics of noise directivity. Valid data-set for an assessment of wind turbine noise was achieved in the range of wind speed bin 8.0 m/s ~ 11.0 m/s at reference 1 position. There are two dominant tonal components near 30 Hz and 80 Hz. Tonal audibility was assessed both frequency bands.