Tutorial summary | |
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Project name | tuto_IPMSM_07 |

Machine name | machine_IPMSM_A |

Source project | tuto_IPMSM_05 |

Description | Same as tuto_IPMSM_05 in partial load |

In this example the no-load project tuto_IPMSM_05_test is copied pasted in a new project named tuto_IPMSM_07_test to find the optimal rotor skew angle with respect to acoustic noise at partial load, fixed speed. Magnetic forces now involve both the fundamental field due to the magnets and due to the armature field.

The variable speed calculation based on load extrapolation is unactivated with

` Input.Simu.type_varspeed=0;`

The partial load is activated using

`Input.Simu.I0 = 10;`

Input.Simu.Phi0 = pi/2;

Input.Simu.is_fixed_load_angle =1;

The speed is fixed at the resonance of the lamination breathing mode close to 6000 rpm:

`Input.Simu.N0=6407;`

`Input.Simu.is_mmfs = 1;`

The single input variable to be varied is the rotor skew angle rate, expressed in stator slot pitch, given by

`Input.Simu.names_var={'skew_rater'};`

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 in [0.8,1.2]

Input.Simu.Nval_contvar=[21]; % 21 values

The output variable that is tracked during the sensitivity analysis is the nominal sound power level:

`Input.Simu.names_resp={'LwrA'};`

The default skew shape is linear, it is defined by the machine parameter Input.Geometry.type_skew_geoR. Finally the electromagnetic skewed model based on 5 magnet segments is activated using

`Input.Simu.type_skew = 2; `

Input.Simu.Nskew_slices = 5;

The noise as a function of the skew rate can be plot using plot_MS_all_resp_var

One can see that **the optimal skew is slightly above one stator slot pitch, which confirms that the optimal skew rate for vibroacoustics depends on the load state**.

The optimal skew value considering all the load points at variable speed can be easily obtained with MANATEE, allowing to define the best magnet inclination angle on the whole torque speed curve considering both torque ripple and acoustic noise criteria.