EM_SPMSM_AL_001

Objective

Validation objective
TopologySPMSM
Model Types Electromagnetic subdomain model EM2.SPMSM
Electromagnetic linear magnetostatic FEM EM3.PMSM
Quantities Airgap radial and tangential armature flux density waveforms
Geometry Internal rotor
Open stator slots and semi-closed slots
Winding Single layer non-overlapping windings with "alternate teeth wound"

Machine

This validation simulates a machine that can be found in the article : L. J. Wu, Z. Q. Zhu, D. Staton, M. Popescu, and D. Hawkins, “Subdomain Model for Predicting Armature Reaction Field of Surface-Mounted Permanent-Magnet Machines Accounting for Tooth-Tips,” IEEE Trans. Magn., vol. 47, no. 4, pp. 812–822, 2011

This SPMSM (Surface Permanent Magnet Synchronous Machine) has 12 stator slots for 4 pole pairs (12s/8p). The airgap field computation is done in 4 distinct subdomains : airgap, stator slots, stator slots openings, and surface permanent magnet (SPM).
Two stator slot geometries are successively explored : opened slots and semi-opened slots.
Stator slots are filled with single layer non-overlapping "concentrated" tooth windings with "alternate teeth wound".
The SPM are unmagnetized, there is only the armature field.
An "exact" semi-analytical subdomain model was developped and compared to FEM, and is the same as for the SPMSM with 6s/4p.

Topology of machine SPMSM_004
Topology of machine SPMSM_004
Manatee model for machine SPMSM_004
Manatee model for machine SPMSM_004

Results

The same model is implemented on MANATEE. The figure below shows the comparison between airgap radial and tangential armature flux density waveforms obtained by both subdomain model and FEMM (See the different Electromagnetic Modules). There is also a comparison between the stator slot configurations.

Publication Radial and Tangential airgap flux
Publication Radial and Tangential airgap flux
Radial and Tangential Airgap Flux (Femm vs subdomain)
Radial and Tangential Airgap Flux (Femm vs subdomain)

The subdomain model is very accurate especially when it accounts for tooth tips, and this enables to compute Maxwell forces much faster than FEM along the airgap and determine electromagnetic forces with armature load (for example electromagnetic torque and cogging torque).

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