This table presents the link between electrical machine design parameters (not control parameters) and magnetic noise & vibration levels (e-NVH), which can be either changed through a change in magnetic excitations (force harmonics caracterized by amplitude, frequencies and wavenumbers) or structural dynamics (caracterized by the electric drive modal basis).
This table gives SIMULIA Manatee a better idea of the design variables which are the most influential on e-NVH, and when MLUT (magnetic forces) or Modal Basis must be updated in Manatee.
| Magnetic circuit parameter | Impact on harmonic magnetic forces | Impact on structural modes |
| Number of poles | Large impact on frequencies and wavenumbers Ex: cogging torque frequency is given by least common between slot and pole numbers times rotor mechanical frequency | Large impact as yoke thickness is generally related to number of pole pairs |
| Number of slots | Large impact on frequencies (for both stator & rotor slot number) and wavenumbers
| Large impact as number of teeth may change tooth thickness and resulting bending mode stiffness |
| Number of phases | Large impact on frequencies and wavenumbers
| Large indirect impact in case of change of slot number or winding mass |
| External Vs internal rotor | Large impact on frequencies and wavenumbers | Large impact as airborne noise resonances change from stator to rotor structure |
| Winding type (concentrated Vs distributed) | Large impact on magnetic force wavenumbers | Significant impact as winding mass / stiffness may be seen differently by tooth/yoke system |
| Short pitch of distributed winding | Significant impact on force harmonics magnitude related to stator magnetomotive force space harmonics | Slight impact (change of end winding weight) |
| Slot shape | Negligible impact, except slot opening Significant impact of slot opening on the magnitude of permeance-related force harmonics | Negligible impact if only slot opening is changed |
| Pole shape / layout | Significant impact on force harmonics magnitude related to rotor flux harmonics in synchronous machines Ex: magnet shaping, V-U magnet layout | Negligible impact |
| Rotor bore shape | Significant impact on force harmonics magnitude related to rotor flux Ex: flux concentration shape, rotor notches | Negligible impact |
| Uneven North / South poles | Large impact on force frequencies and wavenumbers | Negligible impact |
| Stator bore shape | Significant impact on force harmonics wavenumbers related to stator flux Ex: stator notches | Negligible impact |
| Skewing | Large impact on overall force harmonics magnitude | Large impact of rotor modes when going from straight to skewed rotor (change of torsional mode) |
| Airgap width | Significant impact on force harmonics magnitude (they do not necessarily decrease with a larger airgap) | It depends - negligible impact if stator yoke height remains unchanged |
