ALG.EVS Electromagnetic Vibration Synthesis

MANATEE software e-NVH algorithms
Sub-module ALG.EVS
Function Electromagnetic Vibration Synthesis
See also ALG.ENS Electromagnetic Noise Synthesis
ALG.LIA Load Interpolation Algorithm
ALG.LEA Load Extrapolation Algorithm


The accurate calculation of noise and vibrations of electric powertrains requires to evaluate their NVH behaviour at variable speed, taking a high number of speed steps to correctly catch structural resonances. This usually represents a high computational load, as dynamic calculations must be carried at each speed.

MANATEE Electromagnetic Vibration Synthesis (EVS) algorithm aims at speeding up computation of vibrations at variable speed or during optimization loops in detailed design phase of e-motors (based on a 3D FEA structural model).


This module of MANATEE speeds up magnetic vibration calculations while giving more physical insights and transfer path analysis by applying elementary electromagnetic loads in radial & tangential directions (wavenumbers identified automatically by MANATEE) on the linear structural model, calculating the Frequency Response Functions of both rotor and stator, and synthesizing the overall vibration response under operational loads. It can be used with any type of structural model provided in SM (analytic or FEA such as Hypermesh/Optistruct, Ansys, Nastran). The structural FEA model can exist (defined by the user) or be automatically built by MANATEE with SM.NUM option. EVS is particularly useful when a high number of operational loads have to be calculated, for instance in variable speed calculations (e.g. NVH maps on torque speed plane) or in optimization mode (e.g. pole shaping).

Technical details

For further technical details, please see our dedicated article on Electromagnetic Vibration Synthesis.

770. Rotating wave vibration synthesis
Rotating wave vibration synthesis
MANATEE EVS algorithm for fast EV HEV NVH calculation

Graphical post-processing

The complete list of plot commands is available on MANATEE plot commands webpage. The following visualizations are more particularly related to this module:

  • order tracking analysis per load case
  • vibration or noise level of a specific harmonic for each load case



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