With the continually growing number of wind turbine generators (WTGs), the proximity between the installations and residential areas is diminishing, which is why sound emissions have to be kept as low as possible.

WTGs are assessed by means of a complex measurement process that is standardized in line with IEC 64100-11 and presents measurement engineers with particularly demanding challenges. Not only do they have to take external environmental factors as well as ambient and plant parameters into consideration, but they may also need to be able to flexibly intervene in the measurement process to record the requisite measurement data within short periods of time. The plant can then be assessed according to its

• tonality
• sound power and
• third-octave levels.

Localizing Sound Sources

However, not only is the assessment of the plant itself of significance in the development process, but it is also crucial to localize the sources of any interference noise. This can then be correlated with unfavorable events by recording further measurement quantities such as rotational speed, acceleration and electrical power. The appropriate measures can then be taken to eliminate the sources of interference.