Flux e-Machine Toolbox improvements

Reminder: FeMt definition

Flux e-Machine Toolbox is an application in Flux dedicated for Electric Machine. This tool permits to compute and postprocess results dedicated for e-Machine like efficiency maps.

This coupling is available in 2D, 3D and Skew for the magnetic transient application.

The aim of Flux e-Machine Toolbox is to characterize the behavior of the machine in the "Torque-Speed" area and allows to postprocess various quantities in this area.

Input parameters like the maximum phase voltage RMS , the maximum phase current RMS and the desired Maximum speed of the machine are considered.

Two types of command modes are available: The Maximum Torque Per Volt command mode (MTPV) and the Maximum Torque Per Amps command mode (MTPA)

FEMT 2022 improvements

FEMT improvements:

  • Odd periodicities
  • Complete geometries (360° represented)
  • Circuit with delta winding connection
  • New progress bar during solving process
  • Post-process with new command
  • Resume an interrupted test

DELTA or WYE connection

In previous releases only devices containing circuits with WYE winding connection was supported with Altair Flux e-Machine Toolbox. DELTA winding connection is now managed to.

  • On Flux side

    When generating the component for Altair Flux e-Machine Toolbox coupling, only circuits with WYE winding connection was allowed. Now both WYE and DELTA winding connection are supported.

    The dialog box doesn't change. When generating the component, the associated circuit is automatically analysed to know if it's a DELTA or a WYE connection.

  • On FeMt side

    When opening the coupling component in Altair Flux e-Machine Toolbox, the winding connection is now displayed in the settings table, in circuit section.



    During computation, the type of connection "DELTA or WYE" winding connection will be considered automatically to generate the maps.

Resume an interrupted test

During Altair Flux e-Machine Toolbox computations, it happens that Flux fails (for example because of a lack of memory). Previously we were not able to continue a failed test, now in some cases we are able to resume it.

A test is resumable if a crash of Flux happens during the solving stage:



When a test fails and is resumable, a new error dialog is displayed, explaining that is possible to resume this test.



New failed tests during Flux computations are now identified with a new icon if they are resumable.



A new popup menu has been added on these tests to be able to resume it:



After clicking on “Resume” menu item, computations will restart from the last solved step.

制約事項: If a test fails again after resuming, and no step has been solved since resuming, then Altair Flux e-Machine Toolbox will consider it is a definitively failed test and it will not be resumable again.

Odd periodicities

In previous releases, Flux was preventing the generation of a coupling component with odd repetitions number of periodicities. Full motor projects were not properly managed in Flux e-Machine Toolbox neither. In 2022 release, it is now possible to use Flux e-Machine Toolbox with these configurations.

  • On Flux side

    When generating the coupling component for Altair Flux e-Machine Toolbox, limitations according to odd repetitions number of periodicities have been removed, and these configurations are now managed successfully.

  • On FeMt side

    In Altair Flux e-Machine Toolbox, limitations according to odd repetitions number of periodicities and full motor projects have been removed, and these configurations are now managed successfully.

Post-process with new command

In previous releases, if a user wanted to compute a new test with the same inputs from than a previously solved test except for “Command” inputs (“Max. Phase Current, rms (A)”, “Max. Phase Voltage, rms (V)”, or “Command Mode”), he had to run a new test which can be very long.

In release 2022, it is possible to post-process a new test from a previously solved one, modifying only the “Command” inputs, in only few seconds.

In the TESTS table, a new button has been added in the table header. It is enabled when a valid test is selected and it allows to post-process the selected test with new command inputs.



A new popup menu has also been added on valid tests.



Both the button in the header and the popup menu open a “Post-process with a new command“ dialog filled with the selected test values.



Filling the fields with the new customs values and validate the dialog will automatically create a new test in the TESTS table and generate the maps in few seconds.

制約事項: 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