Investigation of small wind turbine noise as per IEC 61400-11 and AWEA 9.1 standard

Abstract

This paper analyzes the noise generated from a 5 kW test wind turbine generator (WTG), having hub height, rotor diameter, cut-in and rated speed of 15m, 4m, 3 m/s and 12 m/s respectively, according to IEC 61400-11 (acoustic noise) standard. It discusses the realistic and comparable performances of small WTG that sets its own characteristics in terms of power and acoustic performances. Standard set by American Wind Energy Association (AWEA 2009) has also been incorporated in this research together with IEC 61400-11. For measuring noise level, the averaging period has been considered to be 10-second as per AWEA 2009. The study attempts to analyze timeseries noise data recorded at different distance from the WTG for finding Noise (dB)- Frequency (Hz), RPM-Volt and Noise-RPM relationship. The current analysis done with the help of wind speed histogram bin each of size 1 m/s estimates that, the ranges of RPM, overall noise and background noise lie between 0 - 170, 45.17 (dB) - 48.78 (dB) and 33.2 (dB) - 65.6 (dB) respectively. The correlation between the WTG noise and background noise indicates for the research that the environmental impact due to noise for the WTG is subject to analyze and may not be underrated.