Aug-Sept 2019 Newsletter: OROS EV/HV module, EVS with skewing, e-NVH workshops

EOMYS / OROS collaboration on EV/HV module

EOMYS regularly carries specialized NVH test campaigns focusing on root-cause analysis of noise and vibration in electric drives. For a more efficient testing process, EOMYS has recently partnered with OROS, who provides NVH test and analysis software solutions, to develop a specialized module for electric motors NVH analysis.

This module, embedded in OROS dynamic acquisition systems, allows to identify the main electromagnetic excitation frequencies and wavenumbers based on e-machine topology, slot/pole combination and load state. This information can then be directly displayed in noise and vibration spectra as "e-markers".

The second feature of OROS EV/HV NVH module is the implementation of the spatiogram technique:

Example of spatiogram obtained with OROS EV/HV module
Example of spatiogram obtained with OROS EV/HV module

Ongoing MANATEE developments

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  • magnetic force wavenumber analysis (decomposition in flux and permeance/mmf waves) for Switched Reluctance Machines (SRM)
  • comparison of several simulation projects outputs (in particular noise & vibration) or several electrical machines
  • numerical Transfer Path Analysis to discriminate noise coming stator excitation or rotor excitation during Electromagnetic Vibration Synthesis algorithm
  • extension of EVS to Electromagnetic Noise Synthesis using in particular Actran
  • axial magnetic force calculations for skewed machines

Zoom on MANATEE feature

The Electromagnetic Vibration Synthesis algorithm of MANATEE can be carried on complex 3D FEA mechanical models especially when the electrical machine is skewed. In case of skewing, the structural model is also excited by force waves with longitudinal force wavenumbers. The resulting Frequency Response Functions then enable to run fast EVS and quickly optimize the skewing pattern with respect to acoustic noise and torque ripple.

Example of MANATEE longitudinal FRF of type (0,1) applied on a 3D FEA mechanical model under Optistruct
Example of MANATEE longitudinal FRF of type (0,1) applied on a 3D FEA mechanical model under Optistruct

MANATEE and e-NVH trainings

Registration to EOMYS next training session on e-NVH and MANATEE software in early January 2020 can be accessed at The two trainings can be registered independently. Trainees can come with their specific e-machine topology to analyze its e-NVH behaviour and optimize it under MANATEE without any knowledge of MANATEE.

Publication of the Month

The publication work of the month is:

L. Roubache, "Conception électromagnétique et vibro-acoustique de machines électriques" (in French), PhD Thesis, Ecole Nationale Polytechnique d’Alger, Algeria, 2019

In this work, SubDomain Modelling technique is developed to speed-up electromagnetic calculations and a semi-analytic vibroacoustic model of the lamination is proposed for e-motor noise simulations, similarly to models implemented in MANATEE software. The multiphysic approach is favourably compared to a fully numerical approach under Ansys Workbench. Saturation is also included in SDM but it then significantly increases computing time, so that SDM can no longer be used in early e-NVH design phase of e-motors.

Conferences and Events

EOMYS is about to organize or participate to the following events related to e-NVH:

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