Acoustic Noise Analysis and Reduction of Electric Motors

Abstract

In this thesis, the acoustic noise emitted by a small electric outrunner motor, such as the ones commonly used in unmanned areal vehicles, is analyzed using a multiphysics simulation based on the finite element method. The simulation covers the electromagnetic, mechanical and acoustic domain. The electromagnetic simulation is performed in the 2D time domain, the mechanical simulation in the 3D time domain and frequency domain and the acoustic simulation in the 3D frequency domain. The difference between results of the time and frequency domain mechanical study is investigated, as well as the difference between the obtained results and those obtained in other available literature. Furthermore, the results are compared to acoustic noise measurements performed in the laboratory. Based on the obtained results, noise reduction methods, specifically focussed on small electric outrunner PMSMs, are proposed and verified using the developed simulation.