An investigation of induction motor zeroth-order magnetic stresses, vibration, and sound radiation

A computational approach is undertaken to better understand what can be one of the primary contributors to sound radiation from induction motors-the n=0 magnetic stresses. An electromagnetic finite-element model, a structural dynamic finite-element model, and an acoustic boundary-element model of an induction motor are used to illustrate some sources of n=0 electromagnetic stresses, and how their resultant vibration field on the stator can be enhanced by boundary conditions, such as stator supports, to result in peaks in the radiated noise spectrum.