Flux e-Machine Toolbox: Postprocessing

Introduction

Once the test running is completed, performance maps are displayed in the central area. The filters on the left allow to display directly the perfomance 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
  • 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.

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.

Post process with new command

It is possible to post-process a new test from a previously solved one, modifying only these “Command” inputs:

  • Max. Phase Current, rms (A)
  • Max. Phase Voltage, rms (V)
  • Command Mode MTPA/MTPV or MTPA Fast/MTPV Fast

The maps will be updated in only few seconds.

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
To posprocess with a new set of command inputs:
  1. Open the Post-process with a new command dialog:
    • In the TESTS table, the button is enabled when a valid test is selected and it allows to post-process the selected test with new command inputs.

      or

    • in the contextual menu available by a right click on a valid test, then by clicking on Post-process with a New Command

    → 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 the maps in few seconds

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