Cancellation of stator or rotor slotting harmonics

By application of the Howtos article "How to cancel stator or rotor slotting harmonics" based on tuto_SCIM_05, in order to cancel stator reluctance harmonics and keep rotor reluctance harmonics, one can put (cf : tuto_SCIM_21):

Input.Simu.is_remove_slotS = 1;
Input.Simu.is_remove_slotR = 0;

In order to keep stator field harmonics only (cf : tuto_SCIM_22):

Input.Simu.is_remove_slotS = 0;
Input.Simu.is_remove_slotR = 1;

In the GUI, these parameters are in Magnetics\Assumption.

One can first check the effect of the command on the permeance using plot_Per_space

Permeance with rotor slotting only (left, 21), stator slots only (middle, 22), and all slotting effects (right, 05)
Permeance with rotor slotting only (left, 21), stator slots only (middle, 22), and all slotting effects (right, 05)
Overall noise level with rotor slotting only (left, 21), stator slots only (middle, 22), and all slotting effects (right, 05)
Overall noise level with rotor slotting only (left, 21), stator slots only (middle, 22), and all slotting effects (right, 05)

These graphs can be obtained using plot_VS_ASPL_overall. Removing the stator slotting effect (for instance, using ideal magnetic wedges) does not completely cancel the acoustic noise due to mmf step harmonics. A resonance still occurs close to 1200 rpm, but it is now due to a winding harmonic as it will be confirmed in the next part.

Removing the rotor slotting effect (for instance, closing the slots without saturation of the bridges) does not reduce the acoustic noise at all, because the stepped rotor mmf harmonics still exist: the acoustic noise that was created due to a combination of mmf harmonics with some rotor permeance space harmonics can still exist due to rotor mmf space harmonics.

In that particular case, one can see that it is much more efficient to work on the reduction of stator reluctance harmonics rather than the rotor ones.

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