Cancellation of stator or rotor mmf space harmonics

By application of the Howtos article "How to cancel stator or rotor space harmonics" based on tuto_SCIM_005, in order to cancel all stator mmf space harmonics and keep only the stator mmf fundamental, one can put (cf : tuto_SCIM_23):

Input.Simu.is_ideal_mmfs = 1;
Input.Simu.is_ideal_mmfr = 0;

In order to impose a sinusoidal rotor mmf (cf : tuto_SCIM_24):

Input.Simu.is_ideal_mmfs = 0;
Input.Simu.is_ideal_mmfr = 1;

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

For tuto_SCIM_23, one can check that the stator mmf does not contain space harmonics any more using plot_smmf_space

Stator mmf before (left, 05) and (right, 23) after removing all space harmonics
Stator mmf before (left, 05) and (right, 23) after removing all space harmonics

For tuto_SCIM_24, one can use plot_rmmf_space

Overall noise level with sinusoidal stator mmf (left, 23), sinusoidal rotor mmf (middle, 24), and all field harmonics (right, 05)
Overall noise level with sinusoidal stator mmf (left, 23), sinusoidal rotor mmf (middle, 24), and all field harmonics (right, 05)

These graphs can be obtained using plot_VS_ASPL_overall. One can notice that in all cases, a significant resonance occurs. This is again because this slotting resonance is linked to the fundamental airgap mmf combined with reluctance harmonics.

The cancellation of space harmonics due to stator mmf does not change the noise profile, which show that the stator winding is not responsible for any of the resonances.

The removal of rotor space harmonics shows and increase in the resonance, which means that some of the force harmonics induced by rotor mmf space harmonics have a destructive interference with the ones linked to stator mmf.

Previous Next