ALG.LEA Load Extrapolation Algorithm

MANATEE software e-NVH algorithms
Sub-module ALG.LEA
Function Load Extrapolation Algorithm (LEA)
Validation ALG_001 ALG_018 ALG_049
See also ALG.LIA Load Interpolation Algorithm


The accurate calculation of noise and vibrations of electric motors requires to evaluate their vibro-acoustic behaviour at variable speed, taking a high number of speed steps to correctly catch structural resonances. This usually represents a high computational load, as operational magnetic loads must be updated at each operating point.

MANATEE Load Extrapolation Algorithm (LEA) algorithm aims at speeding up variable speed calculation of operational magnetic loads in early design phase of e-motors. Using LEA, variable-speed operational magnetic loads can be obtained based on a few single speed simulation and then extrapolated to the full speed range.

Illustration of spectrogram synthesis technique in MANATEE software
Illustration of spectrogram synthesis technique in MANATEE software


LEA is as accurate as quasi-static speed by speed load calculation when the evolution of the magnetic excitation with speed can be predicted in terms of magnitude and frequencies (including rotation direction). As an example, the magnitude of the flux density and resulting Maxwell stress in an open circuit or fixed current angle permanent magnet synchronous machine is independent of speed (except in case of strong dependency of B(H) curve with frequency): excitation frequencies of magnetic force harmonics change with speed (generally proportionally) but their magnitude is unchanged.

LEA accounts for specified control law (e.g. Id/Iq function of speed) and assume no change on saturation level at variable speed. To account for saturation and load effects more accurately at variable speed, especially in more detailed stages, using ALG.LIA (Load Interpolation Algorithm) instead is recommended to speed up load calculation for each operating point.

Technical details

Assumptions of the Load Extrapolation Algorithm can be found in What is Load Extrapolation Algorithm (formerly called synthesized spectrogram)?.

Graphical post-processing

The complete list of plot commands is available on MANATEE plot commands webpage.



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