All machines

Features available in beta mode.

Sometime, a new test is provided in beta mode, meaning that it is not entirely qualified. However, we make it available for testing, and we invite the users to give us their feedback and comments for improving this feature even more.

To indicate the “Beta mode” status of the test, “BETA VERSION” is written in the overview of the considered test as illustrated below.

Here is an overview of the test, as shown below.

Example of a test provided in beta mode

Distribution of computations cannot be used for computing NVH spectrogram (FXM-15772).

Winding – Expert mode – defining of several circuit per sector.

In Expert mode, several parallel circuits can be defined in a sector and moreover several coils can be built in one circuit.

Such circuits can be connected in parallel according to the user’s input No. parallel paths.

In that case, it is mandatory to balance all the parallel paths well while building and connecting the coils inside all the circuits.

Indeed, our internal process of computation doesn’t manage the unbalance between parallel paths, i.e., in the case of unbalanced parallel paths, the results of computations are wrong.
Note: For example, unbalance between parallel paths can be due to the number of coils per circuit, which can be different from one circuit to another. It can also be induced by the building of coils (differences in conductor lengths.

Natural convection for end winding

While choosing a model, where the end spaces are cooled with natural convection, the FluxMotor® model uses quite a low rotor tip speed ratio (a value of 5) to describe the fluid velocity far from the rotating components. This may lead to an overestimation of the cooling of the end winding on high-speed machines.

When a tip speed ratio of 5 seems to overestimate the end winding cooling, it is advised to switch to forced convection mode.

This mode allows forcing some higher tip speed ratios for areas far from the rotor, but reduces the efficiency of the cooling on the end winding.

This model will be improved for future versions.

Transient thermal computations - Displaying of iso-temperatures.

In the test "Performance mapping – Sine wave – Motor – Efficiency map", when a cycle is considered with transient thermal solving, the representation of the temperature iso-values inside the machine can be visualized all along the cycle with an animation.

The animation can run for both the axial and radial views. However, both animations are not well synchronized. Therefore, there can be troubles while using both at the same time.

Modification of units

To take the change of units into account in a test, the user must reopen Motor Factory. The modification is not considered instantaneous in applications of Altair FluxMotor® like Motor Factory.

Preferences – Beta level mode

In the tab “Advanced settings / Preferences”, Altair® FluxMotor® “User Level” can be Standard or Beta. By default, the user level is Standard. In Beta level, the entire qualified features are not available for evaluation.

The FluxMotor® Beta level mode allows performing NVH computations for induction machines – Inner rotor. It gives access to the application “Script Factory”.

Export a model into Flux® environment with represented elementary wires.

  1. Building time of the model in Flux®

    When slots are filled out with a lot of elementary wires, and all the phases need to be represented with solid conductors inside the Flux® 2D model, the resulting python file can be very long. Therefore, the process of building the corresponding model in the Flux® environment can take a longer time.

Browse function

Sometimes, opening a folder from FluxMotor® applications via the browser function requires a longer time (several seconds).

Export environment – HyperStudy®

  1. Compatibility of HyperStudy connectors with respect of FluxMotor solver versions

    The process that describes how to update the HyperStudy connector is written in the user help guide “MotorFactory_2023.1_Introduction.pdf”

  2. New test and connectors for HyperStudy®

    Connectors for coupling FluxMotor® and HyperStudy® are not yet available for the new added tests, like those with transient thermal computations or the tests for induction machine like the “Characterization – Model – Motor – Scalar” and the “Performance mapping – Sine wave – Motor – Efficiency map scalar”.

  3. Mandatory synchronization between connector and FluxMotor versions

    The connectors used in HyperStudy must be synchronized with the FluxMotor solver version.

    An error message (inside the log files) is generated while performing HyperStudy studies with a connector provided with a former version of the FluxMotor solver.

Problems with slot filling

  1. Slot filling is not yet possible with a non-symmetric parallel slot.
  2. When a toothed winding design is considered with rectangular shape wires, the conductor grouping method "horizontal" doesn’t work properly, leading to the wrong visualization of conductors. In that case, it is recommended to select the conductor grouping method "vertical".

    All work well with circular shaped wires.

Example with a toothed winding design (i.e., the coil pitch = 1) and with 2 wires in hand.

Horizontal filling – wrong visualization, but the total number of wires is right Vertical filling – good visualization

NVH computations - Advice for use

The modal analysis and the radiation efficiency are based on analytical computation, where the stator of the machine is considered a vibrating cylinder.

The considered cylinder behavior is weighted by the additional masses, like the fins or the winding, and the subtractive masses, like the slots and the cooling circuit holes.

This assumption allows for a faster evaluation of the behavior of machine in connection to NVH. But in no way can this replace mechanical finite element modeling and simulation.

Possible reasons for deviations in results can be the following:
  • The limits of the analytical model are reached or exceeded.
  • Unusual topology and/or dimensions of the teeth/slots
  • Complexity of the stator-frame structure when it is composed of several components, for instance.
  • The ratio between the total length of the frame Lframe and the stack length of the machine Lstk. In any case, this ratio must be lower than 1.5:

    L_Frame/L_stk ≤1.5