| Tutorial summary | |
|---|---|
| Project name | tuto_IPMSM_06 |
| Machine name | machine_IPMSM_A |
| Source project | tuto_IPMSM_05 |
| Description | Sensitivity study on stator skew angle |
In this example the no-load project tuto_IPMSM_05_test is copied pasted in a new project named tuto_IPMSM_06_test to find the optimal stator skew angle with respect to acoustic noise at no-load, variable speed.
The single input variable to be varied is the stator skew angle rate, expressed in stator slot pitch, given by
Input.Simu.names_var={'skew_rates'};The skew rate is evenly varied from 0.8 to 1.2 stator slot pitch with 21 different values using
Input.Simu.types_var=[0]; %continuous variable
Input.Simu.types_val=[0]; % Value defined by interval
Input.Simu.type_sampling=[0]; % linspace sampling
Input.Simu.bds_contvar={[0.8 1.2]}; %Values between 0.8 and 1.2
Input.Simu.Nval_contvar=[21]; % 21 values
- Setup of skew_rates variation
The output variable that is tracked during the sensitivity analysis is the maximum sound power level calculated from N0_min to N0_max rpm:
Input.Simu.names_resp={'LwrA_max'};
- Workflow group (Sensitivity tab)
The default skew shape is linear, it is defined by the machine parameter
Input.Geometry.type_skew_geoS=0;Finally the electromagnetic skewed model based on 7 slices is activated using
- Numerical group (Magnetics tab)
Input.Simu.type_skew = 2;
Input.Simu.Nskew_slices = 7;A the end of the calculation, the noise as a function of the skew rate can be plot using plot_MS_all_resp_var
- Evolution of LwrA as a function of skew_rates
One can see that the maximum noise at variable speed no-load, which is dominated by a zero-th wavenumber, is minimized close to one stator slot pitch.
The optimal skew angle depends on the type of the force wave responsible for noise and depends on the load condition, so the optimal skew rate is not always one slot pitch.
