Validation objective
Topology BPMSM
Model Types Permeance / mmf electromagnetic model EM1.SPMSM
Analytical structural model SM1
Analytical acoustic model AC1
Quantities Sound pressure level at 1 m in dBA
Geometry V-shaped interior permanent magnet synchronous machine
Winding Fractional-slot winding


The geometry of BPMSM_001 is an Interior Permanent Magnet Synchronous Machine (IPMSM) used for automotive traction application with 18 slot type 23 for the stator and 8 slot type 50 for the rotor.


20. Experimental validation of the variable speed sound pressure level
Experimental validation of the variable speed sound pressure level

MANATEE software correctly predicts the two main resonances due to magnetic forces, and the sound pressure level (SPL) at 1m away from the machine at resonance is within 5 dB despite degraded acoustic measurement conditions and unknown damping. Some differences of SPL are due to PWM harmonics present in the experiments but not in MANATEE due to missing control data, and to mechanical noise present in tests and not in MANATEE. The machine is water cooled so no aerodynamic noise is present in test data.

The first resonance is due to magnet / stator slot interaction at no-load, and the second one is due to armature field at partial load. Both resonances excite the elliptical mode of the stator lamination. A modal damping of 2% (default value of MANATEE structural model) is used.

A redesign of this machine gave 40 dB reduction and this reduction was validated with experiments:

40 dB noise reduction with MANATEE
40 dB noise reduction with MANATEE
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