Radial force as a function of space (plot_Fr_space)

Post-processing documentation
Matlab commandplot_Fr_space
Module EM.pp
Description PLOT_FR_SPACE plots the airgap radial magnetic force per unit area as a function of space
See also plot_Ft_space, plot_Fr_time, plot_Fr_fft2


The calculation of Maxwell tensor is an important output of MANATEE software electromagnetic model as it generates magnetic forces responsible for electromagnetically-excited audible noise.

This particular post processing plots the radial force per unit area experienced by the outer structure as a function of airgap angle, including the corresponding Fourier analysis:

Airgap radial force as function of space
Airgap radial force as function of space

One can see that it is negative because globally the outer stator tends to be pulled towards the inner rotor.

The largest harmonic (wavenumber) should correspond to r=2p (twice the number of pole pairs) and its magnitude should equal the DC component one (r=0). Note that only the lowest force wavenumbers are important in magnetic noise and vibration process.

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 radial force is available with plot_Fr_fft2.

To change the default plot options (e.g. time stamp of the plot, axis) you can read How to change post processing plot options ? article.

This graph helps identifying the space harmonics involved in radial magnetic pressure involved noise and vibration behaviour of the electrical machine.

Previous Next