Fixed-speed sinusoidal current-driven partial load vibro-acoustic simulation with permeance / mmf model

Tutorial summary
Project name tuto_IPMSM_03
Machine name machine_IPMSM_A
Source project tuto_IPMSM_02
Description Same as tuto_IPMSM_02 but partial load

The project tuto_IPMSM_02_test can be copied/paste (or loaded and saved with the GUI) in tuto_IPMSM_03_test to create a new current driven electromagnetic and vibroacoustic simulation at partial load using permeance/mmf model.

The first thing to carry partial load calculation in the PMSM is to activate the calculation of the stator armature field using

Electromagnetic group (Assumption panel)
Electromagnetic group (Assumption panel)
Input.Simu.is_mmfs = 1;

One can then impose arbitrarily the phase current values of the armature field and the PM rotor position independently; alternatively, one can also fix the current angle in the DQ frame to achieve a certain torque amount.

The RMS phase current can be imposed using


This means the equivalent circuit is not used to calculate stator currents. The magnitude and phase of the current in the ABC frame are then specified by

Input.Simu.I0 = 150;
Input.Simu.Phi0 = pi/2;

In the GUI, you can set this parameter in Workflow (type_extsupply is set by "Input: Current sinusoidal"):

Workflow group (Simulation tab)
Workflow group (Simulation tab)

For surface permanent magnet motors in motor mode, Phi0=pi/2 gives the maximum output torque. When specifying a specific current angle, the rotor position should be synchronized with the stator field using (default hidden value in the GUI):

Input.Simu.is_fixed_loadangle = 1;

In this example, an id current of -30A and iq current of +39A is simulated using

Input.Simu.I0 = sqrt((-30)^2+39^2));
Input.Simu.Phi0 = atan(39/(-30));

One can notice that the magnetic force spectrum now contains a new pulsating (wavenumber r=0) component using plot_Fr_fft2 :

FFT2 of radial pressure on stator
FFT2 of radial pressure on stator

This is also the case of the sound power level spectrum obtained with plot_ASWL_fft :

A-weighted sound power level spectrum
A-weighted sound power level spectrum

Again the simulation time is extremely fast (max 2 second) and the spectrum is obtained up to 20 kHz, maximum of the human’s ear sensitivity.

The Load Extrapolation Algorithm at variable speed can be used but then the variation of id/iq has to be defined with the control type:


For type_control=0 the current angle and current magnitude is kept unchanged with speed. Using type_control=8 one can specified the current angle and current magnitude as a function of speed in Input.Simu.I0spec (phase current magnitude) and Input.Simu.Phi0spec (phase current angle).

The variable speed noise and vibration including structural modal contribution can be plot with plot_ASWL_modal_cont

Order contribution to A-weighted global noise
Order contribution to A-weighted global noise

One can see that the resonances are still close to 3000 and 6000 rpm due to 12th and 24th times the electrical frequency with the 0-mode of the lamination stack.

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