Result interpretation : Text Output

The overall text output should look like this:

MANATEE simulation text output
MANATEE simulation text output

If one wants to remove all the text outputs in the command line, the parameters Input.Simu.is_com must be set at 0.
Some warnings may appear, one should carefully read them and check that they do not represent an issue. Here, the last warning deals with the constant flux sonogram, which might be incorrect at low speed due to numerical limitations.

In the following text output one can find the theoretical vibroacoustic study:

Theoretical vibroacoustic study
Theoretical vibroacoustic study

This table sweeps the slotting force harmonics of the induction machines and identify potential harmful force harmonics. These harmonics represent both radial and tangential force harmonics.

  • The wavenumber r is the spatial frequency (half the number of circumferential nodes) of each force wave.
  • The integers kr and kr are the ranks of the slotting permeance harmonics (ranks of the Fourier transform of the airgap reluctance), due to respectively rotor slots and stator slots.
  • The variable eps equals +/-1 in the wavenumber expression r for slotting harmonics, and +/-2 for saturation harmonics.
  • The variable k is the proportionality factor between the force harmonic frequency and the fundamental stator frequency.
  • The boolean resonance indicates if there is a resonance that should theoretically occur, based on the minimum and maximum speed specified, and based on the natural frequencies calculated by the structural model (in our case, a 2D analytical model).
  • freso indicate the supply frequency at which this resonance occurs.
  • Nreso indicate the speed at which this resonance occurs.

The lower are kr and ks, the higher are the reluctance harmonics magnitude and the higher are vibration and noise at resonance. In this example, one can notice a high force harmonic of wavenumber r=-2=Zr-Zs+2p=28-36+6 and frequency fs((1-s)Zr/p+2) that theoretically resonate with the stator ovalization mode near 1170 rpm. In practice kr and ks values above 4 should not raise any acoustic issue.
Another important force line (kr=ks=1) is given by r=-8=Zr-Zs, but it does not make any resonance in theory (forced excitation of the stack).

Note that this theoretical study does not include higher space harmonic effects, in particular the space harmonics present in the stator winding mmf.

The next text outputs sums up the main parameters of the machine:

60. Machine main parameters
Machine main parameters

The rotation direction of the main flux is determined based on the winding pattern. To reverse the rotation direc-tion one can permute the phase in the simulation project using Input.Simu.perm_cur=[2,1,3]

60. Machine main parameters
Machine main parameters

Here one can check the slot fill factor and the weight calculation.

60. Discretization output
Discretization output

Here one can check the discretization is high enough.
The maximum rank of slotting harmonics should be above 5.
The characteristics of the equivalent circuits are given:

60. Equivalent Circuit
Equivalent Circuit

The electrical outputs are summarized:

60. Electrical Output
Electrical Output

The vibration model outputs are summarized:

60. Vibration model output
Vibration model output

The acoustic model outputs are summarized:

60. Acoustic model output
Acoustic model output

Note that the numerical accuracy of MANATEE acoustic noise calculation is lower than +/-0.3 dB.

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