e-NVH

Welcome to the “e-NVH Academy” of EOMYS!

In this section you will find online resources dealing with magnetic noise and vibrations in electric motors. e-NVH means “electromagnetically-excited Noise, Vibration and Harshness” or “electrical NVH” to refer to noise and vibration behaviour of electrified systems. A more general term for all applications is “electromagnetically-excited noise and vibrations”.

The aim of these online resources is to provide educational materials for both electrical engineers and NVH test engineers to learn:

the origin of electric motor whining noise and electromagnetically-excited vibrations (e-NVH) the electromagnetic and structural design parameters that are the most influential on electric motor noise and vibrations the noise and vibration reduction techniques which can be applied at design stage or after manufacturing of electrical machines

These resources are parts of EOMYS detailed technical training on magnetic noise and vibrations in electrical machines and passive components. They include:

articles and technical notes on NVH of electrical machines sound samples related to electromagnetic noise videos related to electrical machine noise & vibrations conference materials on e-NVH webinars on vibro-acoustics of electrical machines

To keep up with new e-NVH materials you can subscribe to our monthly newsletter.

What is the effect of current harmonics?

Definition The theory of AC (Alternative Current) rotating machines considers sinusoidal supply currents, but in reality it is usually composed of an addition of multiple harmonics. For a given phase,

[ICEM 22] Magnetic noise control of e-machines: best practices for electrical engineers

This tutorial on magnetic noise control techniques of electric machines was presented at the International Conference on Electrical Machines in Valencia, 5th September 2022 by J. Le Besnerais. The tutorial

What is the room equivalent absorption area?

Definition The room equivalent absorption area, , is used to characterize the acoustic absorption capacity of a room. The acoustic absorption of a given room is linked to its wall

What is the effect of temperature on e-NVH?

Impact on excitations Temperature can first influence electromagnetic excitations (e.g. slotting harmonics) responsible for magnetic noise in electric machines. It is already known that cogging torque varies with temperature due

[Aachen Acoustics Colloquium 21] Perceived sound quality analysis of Electric Drive Units under different switching control strategies

The noise emitted by Electric Drive Units (EDU) of Hybrid Electric Vehicles or full Electric Vehicles (HEV/EV) is a key contributor to the overall perceived quality of the vehicle. This

[SIA-CTTM Automotive NVH Comfort 21] Noise due to electromagnetic forces in automotive application

Acoustic noise sources in Hybrid Electric Vehicles or full Electric Vehicles (HEV/EV) must be controlled to guarantee an adequate level of acoustic comfort to both passers-by, drivers, and passengers. This

[IOA NVEG 21] Noise due to electromagnetic forces in automotive application

Electromagnetic forces can be a major source of unpleasant noise in electric machines. The presentation focuses on understanding how magnetic noise and vibration are generated by slotting harmonics and switching

[SAE NVH 21] Fundamental understanding of Vehicle Electrification & Motor Drive NVH Workshop

EOMYS presents at SAE Noise Vibration Conference on 7th September 2021 Grand Rapids (USA) a technical workshop on Electromagnetic Noise Vibration Harshness of e-motors in automotive applications. The presentation can