Vibroacoustic Analysis of an Electric Motor with Reduced Rare Earth Content

The recent revolution in land vehicle traction systems brings new challenges to manage, such as the vibroacoustic emission generated by electric motors. This study presents a robust strategy for magneto-structural coupling using finite element analysis to investigate the phenomena governing the vibroacoustic emissions of an electric motor. The work focuses on an interior permanent magnet synchronous motor modified from its original layout. Specifically, the number of permanent magnets in the rotor has been significantly reduced to minimize the use of rare earth materials and decrease the environmental impact associated to the electric motor production. The methodology is divided into several phases: initially, the radial forces exerted on the stator teeth are calculated; subsequently, an in-depth modal analysis is performed on the stator and housing; finally, the forcing functions are applied to the structural model to evaluate the vibroacoustic response under the applied excitations. The sound pressure level is estimated in decibels using a boundary element method model, providing a detailed and quantitative assessment of the electric motor's acoustic emissions.