Airgap radial flux density as a function of space (plot_Br_space)

Post-processing documentation
Matlab commandplot_Br_space
Module EM.pp
Description PLOT_Br_SPACE plots the airgap total radial flux density as a function of space
Parameters
Restrictions
See also plot_Bt_space, plot_B_time, plot_Br_surf, plot_Br_cfft2

Result

The flux density distribution is the main output of the electromagnetic model of MANATEE software as it is used to calculate the Maxwell stress tensor responsible for electromagnetically-excited audible noise.

This particular post processing plots the radial airgap flux as a function of airgap angle, including the corresponding Fourier analysis:

Airgap radial flux density as a function of space
Airgap radial flux density as a function of space
plot_Br_space

The largest harmonic should correspond to the number of pole pair (displayed in red).

In this example of an induction machines with Zs=36 stator slots and Zr=28 rotor slots and p=3 pole pairs, one can see significant slotting harmonics at Zs-p=33 and Zs+p=39 due to stator slots and stator stepped magnetomotive force. The rotor slotting effect at Zr-p=25 and Zr+p=31 is smaller due to the fact that rotor slot openings are much smaller compared to stator slot openings.

Note that this 1D FFT graph gives only a partial view of the harmonics, as both space and time frequencies are involved in noise and vibration generation. A 2D Fourier transform of the flux is available with plot_Br_cfft2.

To change the default plot options you can read How to change post processing plot options ? article.

This graph help identifying the space harmonics involved in flux density which may affect the noise and vibration behaviour of the electrical machine.

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