December 2023 news: Manatee release 2.2.6, stator structural modes and noise reduction techniques, PhD thesis, next conferences

Manatee e-NVH software news

In October, EOMYS published a new version of Manatee software. V2.2.6 has been released with the following new features: 

  • definition of Permanent Magnet Synchronous Machines with different North/South poles
  • enriched and improved parametrized templates of slots, notches, and magnet holes
  • improvements on DXF / Flux / Modal Basis import interfaces
  • possibility to define a parameter sweep on magnetic temperature

This month, the development team has worked to improve the stability and memory usage of Manatee. New algorithms have been developed and validated to quickly assess noise and vibrations due to Pulse Width Modulation. Several tutorials have been written for electrical, mechanical and NVH engineers and will be soon available on Manatee website.

Manatee trial license allows you to draw your own electrical machine, import your 3D FEA modal basis, and calculate its magnetic noise and vibration levels at variable speed – contact us if you want to explore its many options to assess and control noise and vibrations in electrical machines.

Stator structural modes

We have summarized the most important stator structural modes for you which should be identified for troubleshooting or predicting acoustic noise and vibrations induced by electromagnetic forces.

  1. Stator breathing modes, which can be excited by radial magnetic forces r=0 (which occur at cogging torque / torque ripple frequencies in PMSM)
  2. Stator elliptical modes, which can be excited by radial & tangential magnetic forces of r=2 (e.g. when Greatest Common Divider between slots & poles is 2)
  3. Stator torsional modes, which can be excited by circumferential magnetic forces r=0 (e.g. at cogging torque / torque ripple frequencies in PMSM)
  4. Stator bending modes, which can be excited by unbalanced magnetic forces (e.g. UMP harmonics induced by eccentricity)

Noise reduction techniques in images

Better described with images than with words! Find below a summary of e-NVH reduction techniques that can be investigated with Manatee software. 

Reduction techniques applied to magnetic noise radiated by e-motors are split into three main families:

  1. electrical solutions
  2. control solutions
  3. structural solutions

The order of magnitude of the maximum noise reduction in dB is given based on the experience of EOMYS.

PhD thesis

Cedric Marinel first joined EOMYS as a software engineer some years ago and then decided to pursue an industrial PhD work on video-based modal analysis in collaboration with CRIStAL Laboratory of Lille. After a three-year research work at the edge of structural dynamics and signal processing, he successfully defended his PhD thesis on 29th November, and we are happy to have him back in our scientist team to support our R&D activities and the development of Manatee software. 

Training planning in 2024

EOMYS decided to perform most of its technical trainings on magnetic noise & vibrations in the framework of Manatee software licences. Indeed, each Manatee licence comes with general training on e-NVH basics, with customized training on Manatee applied to the electrical machine of the customer, and a unique package of e-NVH support hours which can be used for additional training by our e-NVH consulting engineers.

Conferences to come in 2024

We have not yet completed all the arrangements, but two conferences have been confirmed for next year: EOMYS will be at Internoise 2024 in Nantes, France and ICEM 2024 in Torino, Italy.

Feel free to contact us to arrange your preferred appointment on-site!