Inputs

Standard inputs ––––--

No standard user input is needed.

Advanced inputs ––––--

No. comp. / cogging period

The computation of cogging torque versus the rotor angular position is performed using a Finite Element Modeling.

“No. comp. / cogging period” (Number of computations per cogging torque period) influences the accuracy of results and the computation time.

The default value is equal to 45. The minimum allowed value is 13. This default value provides a good compromise between the accuracy of results and computation time.

Max. harmonic order

The cogging torque is computed over one cogging torque period.

Harmonics are extracted from the frequency analysis (F.F.T. Fast Fourier Transform) of the cogging torque signal versus rotor angular position.

Rotor initial position

The computations are carried out by considering a given initial relative angular position between the rotor and the stator.

This initial relative angular position of the rotor must be set in the field « Rotor initial position».

This relative angular position corresponds to the angular distance between the direct axis of the rotor north pole and the axis of the stator phase 1 (reference phase). The default value is equal to 0. The range of possible values is [-360, 360].

For additional information please refer to the section Rotor initial position (link).

Skew model – No. of layers

Airgap mesh coefficient

The advanced user input “Airgap mesh coefficient” is a coefficient which adjusts the size of mesh elements inside the airgap. When the value of “Airgap mesh coefficient” decreases, the mesh elements get smaller, leading to a higher mesh density inside the airgap, increasing the computation accuracy.

The imposed Mesh Point (size of mesh elements touching points of the geometry), inside the Altair Flux software, is described as:

MeshPoint = (airgap) x (airgap mesh coefficient)

Airgap mesh coefficient is set to 1.5 by default.

The variation range of values for this parameter is [0.05; 2].