Flux e-Machine Toolbox: Postprocessing


Once the test running is completed, performance maps are displayed in the central area. The filters on the left allow to display directly the performance map wished. The user has the possibility to use a cursor to display values by pointing on the map.

Performance maps

Several quantities are postprocessed in the Torque-Speed area:

  • Efficiency
  • Phase current
  • Phase voltage
  • Control angle
  • Mechanical power
  • Iron losses in rotor and stator
  • Iron losses in rotor
  • Iron losses in stator
  • Stator winding Joule losses
  • Rotor Eddy current losses
  • Total losses: the sum of these 3 types of losses
Warning: With the two command modes MTPA Fast and MTPV Fast, the Iron losses and the Eddy current losses are not computed. The two corresponding maps are therefore not available.

Efficiency map manipulations


The user can display efficiency map values at the cursor position.

Scale modification

It is possible to modify the scales of all efficiency maps:

  • graphically
  • manually
Steps for graphical modification of scales
  1. Click on
  2. On the efficiency map, do a rectangle selection

    → Map rebuilding takes a few seconds

    → Recomputed efficiency maps are updated

    Before modification After modification

    → Values are updated

Steps for manual modification of scales

  1. Edit the value you want to modify

  2. Modify the wished value and validate with the Enter key

  3. Edit and Modify other values if you want

  4. Validate all modifications by clicking on

    → Map rebuilding takes a few seconds

    → Recomputed efficiency maps are updated

    Before modification After modification
Important: The modification is applied to all displayed efficiency maps.
Note: After modification, it is possible to reset the scale values by clicking on
Note: These modifications are only taken into account when displaying efficiency maps. The new values are not taken into account when exporting a test.

Skew specificity

In Flux, the description of a Skew model is done in the 2D environment. The 3D device is then rebuilt for the postprocessing. The face regions become volume regions.

Since FeMT 2021, for Skew projects, the iron losses are now computed on non-conducting laminated magnetic regions only.

From now on, for Skew projects, for the iron loss computation:
  • It is mandatory to use non-conducting laminated magnetic regions for the stator and the rotor.
  • It is recommended to define a material with losses model and to assign it to non-conducting laminated magnetic regions (stator and rotor), otherwise default parameter values will be used for the iron loss computation.
Note: For FeMT versions prior to 2021, for Skew projects:

The iron losses were only computed on the non-conducting magnetic regions, because the laminated regions did not exist in Skew. In this case, the default Bertotti coefficients were applied after the end of the Flux solving process.

(K1=151.88 ; K2=0.07 ; K3=1.19 ; A1=2 ; A2=2 ; A3=1.5)

Note: About FeMT Skew coupling components generated from Flux version 2020.1 or older:

FeMT 2021 no longer supports computation of iron losses for older Skew projects with no laminated regions.

However, the old Skew projects can be opened in FeMT 2021 and results of previous simulations computed with older FeMT version can be displayed. But, it is not possible to start a new simulation on this old project.

In order to run a new simulation on this old project, you will have to open your Skew project with Flux 2021 and regenerate a FeMT coupling component.

Quick run with new parameters

It's possible to create and run a new test with new values of some parameters. The possible parameters to modify are the parameters which no need a re-solving of the Flux project, but only a re-compute and re-display of maps.

The possible parameters to modify for a quick run are:

  • Torque Computation Mode
  • Max. Phase Current, rms (A)
  • Max. Phase Voltage, rms (V)
  • Command Mode (MTPA/MTPV or MTPA Fast/MTPV Fast)
  • X Factor (applied to Iron Losses)

The maps will be updated in only few seconds.

Here are the steps to quickly run a test:
  1. Open the Quick run with new parameters dialog box:

    Display the wished test by double click on it.

    → the test are displayed on the center area in a new tab

    → The ribbon with Quick Run button appears

    Note: It's also possible to open the Quick run dialog box:
    • by selecting the test in the list and by clicking on
    • or by a right-click on the test and by selecting in the contextual menu → Quick run

    → the dialog is opened

  2. Fill the fields with the new customs values and validate

    a new test is automatically created in the TESTS table and the maps are generated in few seconds

Possible parameters to modify for a Quick Run

Torque computation mode

  • For the torque computation, the Useful mode is only available with the MTPA and MTPV command modes (for which the iron losses are computed).
  • With the MTPA Fast and MTPV Fast command modes, the iron losses are not computed, so the Useful mode is not available, the torque will therefore be computed with the Electromagnetic mode.
Note: For the tests run with a version prior to 2023.1, with the MTPA and MTPV command modes, it is possible to rerun the torque computation with the Useful mode using a version later than or equal to 2023.1.

Max. Phase Current, rms (A)

Restriction: Because of the extrapolation process used to compute the post-processed test with new command, the new value for “Max. Phase Current, rms (A)” should follow the constraints bellow:
  • Imax is the initial value of the “Max. Phase Current, rms (A)”. It will always be the value of the original fully computed test, even if the test is post-processed from another post-processed test.
  • Then ImaxNew should be 0.5*Imax ≤ IMaxNew ≤ Imax otherwise extrapolation may cause accuracy loss. A warning message is displayed in that case.

  • ImaxNew < √2*Imax otherwise an error message will be displayed

Command mode

Warning: It is possible to modify the command mode but using the same solving workflow only.
  • If you use the standard solving workflow, it is possible to switch:
    • from MTPA to MTPV
    • from MTPV to MTPA
  • If you use the fast solving workflow, it is possible to switch:
    • from MTPA Fast to MTPV Fast
    • from MTPV Fast to MTPA Fast