Acoustic Emission Characterization of Six Wind Turbines: A Diagnostic Tool to Isolate, Identify, and Quantify Point Source Contributors to a Wind Turbine’s Noise

The diagnostic tool developed in this study was designed to perform acoustic analyses to enhance the International Electrotechnical Commission’s (IEC) 61400-11, edition 2.1 Standard. The IEC Standard, which is the current international standard for collecting wind turbine acoustic data, describes a methodology for measuring, characterizing, and reporting wind turbine acoustic emissions. The developed diagnostic tool uses enhanced tonal analysis to allow for identification of peak frequencies and a more detailed characterization of a turbine’s acoustic emissions. In this study, the IEC Standard 61400-11 methodology was followed for acoustic and meteorological data acquisition for six wind turbines. Band pass filters isolated individual peak frequencies to identify and quantify individual point source contributors to a wind turbine’s acoustic emissions. Through specific mathematical conversions, a linear comparison of sound pressure levels was performed for relative quantification. Each identified sound pressure percentage was then associated with a point source contributor through application of a decision tree developed for this study. The diagnostic tool has shown to illustrate a process that presents concise acoustic information that may be useful to wind turbine manufacturers to target specific major component contributors for mitigation and subsequent reduction of their wind turbines’ acoustic emissions.