With the advent of power electronics, there has been an increasing demand
for variable speed drives which offer substantial energy savings. However,
the use of frequency converters in driving induction motors can lead to
significant increase in acoustic noise levels. In this talk, various noise
sources in electric motors will be described. The effects of different
control strategies on the noise produced will be discussed. Finally,
results obtained by finite element/boundary element methods and statistical
energy analysis to predict the radiated noise from variable speed induction
motors will be presented.