Predicting acoustic noise in high-speed permanent magnet machines

This paper presents a methodology for predicting the acoustic noise produced by an ultra high-speed permanent magnet synchronous machine (PMSM). A multi-physics approach is used, combining electromagnetic, structural and acoustic simulations to produce an accurate prediction of the motor’s acoustic output using various software packages within Ansys Workbench. The process begins with a 2D electromagnetic simulation to calculate the harmonic forces acting on the stator teeth. These forces, along with the results of a modal analysis, are then imported into a 3D mechanical model to carry out harmonic response and harmonic acoustic analysis. Finally, the acoustic results are imported into an acoustic post-processing tool to generate a predicted sound file of the motor across a speed sweep from 40,000-120,000 RPM.