e-NVH response synthesis of electric motors based on stator teeth FRF measurements

Abstract

The analysis of noise and vibrations under electromagnetic excitations (e-NVH) in electrical machines requires to study the stator mechanical response when excited by Maxwell stress waves. In particular, the notion of unit-wave Frequency Response Function (FRF) is often used in e-NVH simulations to model the mechanical response under electromagnetic excitations and troubleshoot noise issues. However, it is not possible to directly measure the unit-wave FRF on the electrical machines and validate the model. Instead, the Experimental Modal Analysis (EMA) is often compared to a Finite Element (FE) model in order to fit the numerical parameters (damping, boundary conditions, etc.). This paper is presenting a complementary approach to fully numerical e-NVH analysis. It is a new hybrid methodology based on experiments for the mechanical FRF and simulation for the magnetic excitations. This is performed with dedicated experimental measurements and post-processing. The new methodology builds an equivalent unit-wave FRF from experimental measurements. The methodology is validated with the diagnose of electromagnetic noise issues for an experimental benchmark Surface Permanent Magnet Synchronous Machine (SPMSM).