Variable-speed, sinusoidal current-driven, partial-load simulation

Tutorial summary
Project name tuto_BPMSM_04
Machine name machine_BPMSM_A
Source project tuto_BPMSM_03
Description Variable speed simulation at constant current

We have seen in the previous step of the tutorial Fixed-speed sinusoidal current-driven partial load vibro-acoustic simulation with permeance / mmf model that the synthesized sonagram assumes that the current angle is kept constant along the whole speed curve.

It is however possible to run a specific variable speed simulation at constant current while changing the current angle as a function of speed. This can be done in a separate project tuto_BPMSM_04_test by copy/paste (or load/save with the GUI) of tuto_BPMSM_03_test.

The variable speed mode is activated using

Input.Simu.is_varspeed = 1;

The number of speed steps, the min and max speeds are still defined


The control law to be applied at variable speed must therefore be speficied. The variation of the current magnitude and current angle with speed is obtained by specifying

Input.Simu.type_control = 8;

To follow the constant torque/speed curve specified in the reference article at 60 Nm, the following points are specified in the machine file BPMSM_48s8p:

Input.Electrical.N0spec = [0 500 1000 1500 2000 2504 3304 4104 4904 5704 7000];           % rotation speed [rpm]
Idspec=[50 40 30 15 0 -30 -57 -77 -97 -115 -150];
Iqspec=[110 100 85 75 50 39 30 26.4 23.6 23.8 20];

% RMS phase current [A]
Input.Electrical.I0spec = sqrt(Idspec.^2+Iqspec.^2);      
% electrical angle [rad]            
Input.Electrical.Phi0spec = mod(atan(Iqspec./Idspec),pi);                              

In the GUI, all these parameters are in Workflow:

150. Workflow group (Variable speed tab)
Workflow group (Variable speed tab)

You can also preview the control that you entered:

150. Control law preview
Control law preview

The obtained sound pressure level can still be obtained with plot_VS_ASPL_overall

140. A-weighted variable speed sound pressure level
A-weighted variable speed sound pressure level

One can see that the resonances close to 3000 and 6000 rpm present at no-load are still here, but the magnitude of the maximum levels are different: this is because some destructive or constructive interference occur between armature-induced force harmonics and magnet-induced force harmonics.

The valued of id and iq currents can be checked after the calculation using plot_VS_var(’Id0’) and plot_VS_var(’Iq0’):

Evolution of Id0
Evolution of Id0
Evolution of Iq0
Evolution of Iq0
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