[ISMA] Characterization of EV/HEV NVH Issues using Electrical Machine Tooth FRF

AuthorsKarine Degrendele ; Jean Le Besnerais ; Raphaël Pile; Paul Gning; Emile Devillers;
StatusAccepted in ISMA 2020
Date7-9th September 2020
KeywordsElectrical machines, powertrain, e-NVH simulation, Frequency response function, Mechanical engineering


This conference article extends the use of tooth Frequency Response Functions (FRF) concept for the analysis of electric motor Noise, Vibration and Harshness due to electromagnetic forces (e-NVH) at intermediate design stage or after manufacturing, using both simulation and testing. The principle consists in first characterizing the structural response of the housing envelope when exciting stator teeth under harmonic loads. Then tooth FRF can be converted to wave FRF to analyze the structural response under rotating Maxwell stress waves. These wave FRF can be used for modal parameter extraction, or to study the effect of eccentricities by modulating pulsating magnetic forces driving the NVH behavior of e-motors in electric and hybrid electric vehicles (EV / HEV) automotive applications. Besides, tooth FRF can be used to visualize the operational magnetic force waves acting on the stator using Operational Force Shape analysis. Longitudinal FRF concept is also introduced to study skewing effects and optimize the skewing pattern combining tests with simulation under MANATEE software, specialized on the electromagnetic and vibroacoustic design of electric motors. Finally, the extension of the concept on stator FRF to rotor FRF is discussed.


The conference article can be downloaded here: