Inputs

1. Introduction

The total number of user inputs is equal to 10.

Among these inputs, 4 are standard inputs and 7 are advanced inputs.

2.1 Line-Line voltage, rms

The rms value of the Line-Line voltage supplying the machine: “Line-Line voltage, rms” ( Line-Line voltage, rms value ) must be provided.

Note: The number of parallel paths and the winding connection are automatically considered in the results.

2.2 Power supply frequency

The value of the power supply frequency of the machine: “ Power supply frequency ” ( Power supply frequency ) must be provided.

The power supply frequency is the electrical frequency applied at the terminals of the machine.

2.3 Operating mode

The computation of the test « Performance Mapping / Sine Wave / Motor / T(Slip) » is performed by considering the machine operating mode. The selected operating mode can be “Motor”, “Generator”, “Brake”, “Motor & Generator”, “Motor & Brake” or “Full”.

According to the operating mode the resulting range of slip is automatically defined as illustrated in the following table.

 Operating mode Resulting range of Slip Motor [0,1] Generator [-1,0] Brake [1,2] Motor & Generator [-1,1] Full [-1,2]
Note: The considered used convention is the motor one.

2.4 User working point - Slip

The value of the targeted slip for the user working point “User working point - Slip” ( Slip at the targeted working point ) must be provided. This value must be in the range of slip corresponding to the selected operating mode.

3.1 Slip distribution mode

The computation of the test « Performance Mapping / Sine Wave / Motor / T(s) » is performed by considering a distribution of computed points. The user’s input “ Slip distribution mode ” ( Select the method for the distribution of computed points ) gives three possibilities to the user:

1. Slip distribution mode = Logarithmic

When “Logarithmic” is selected, the distribution of the computed points is automatically done. The number of computations to be done in the slip range must be set in the next field: “No. comp. in slip range”.

2. Slip distribution mode = Linear

When “Linear” is selected, the distribution of the computed points is automatically done. The number of computations to be done in the slip range must be set in the next field: “No. comp. in slip range”.

3. Slip distribution mode = Table

When “Table” is selected, the list of slips to be considered must be defined by using the next field: “Slip table” and by clicking on the button “Set values”.

Two ways are possible to fill the table: either filling the table line by line or by importing an excel file where all the slips to be considered are defined.

Note: The slips must be listed in ascending order.
 Slip distribution mode = Table 1 Select the “Table” option. 2 Click the button “Set values” of the field “Slip table” to open a dialog box to define the list of slips to be considered.Refer to the next illustration which shows how to fill the Slip table. 3 Button to validate and consider the user inputs 4 Button to run the computation
 Slip distribution mode = Table – Dialog box to define the list of slips 1 Dialog box opened after clicked on the button “Set values” in the field “Slip table” 2 Browse the folder to select an Excel file which is defined the list of slips 3 Button to refresh the table data when the considered Excel file has been modified 4 Fields to be filled with data to describe the considered slips 5 Button to apply the inputs 6 Button to erase the data table
Note: The Excel template used to import a list of slips is stored in the folder Resource/Template in the installation folder of FluxMotor. An example of this template is displayed below.
 Excel file template to define the list of slips
Note: The slips must be listed in ascending order.

3.2 Number of computations in slip range

When the slip distribution mode is “Logarithmic” or “Linear”, the “ No. comp. in slip range ” ( Number of computations for the whole domain corresponding to the slip range ) must be provided.

Note:
1. The default value is equal to 15 when the selected operating mode is “ Motor ” or “ Generator ” or “ Brake ”,

The default value is equal to 29 when the selected operating mode is “ Motor & Generator ” or “ Motor & Brake ”,

The default value is equal to 44 when the selected operating mode is “ Full ”.

2. The minimum value allowed is 7.
3. Default values are chosen to get a good compromise between the accuracy of results and computation time

Note 2:

Note 3:

3.3 Slip table

When the choice of point distribution mode is “ Table ”, the list of slips to be considered “ Slip table ” ( Slip table ) must be provided. Refer to the above section 3) Slip distribution mode = Table

3.4 Skew model – No. of layers

When the rotor bars or the stator slots are skewed, the number of layers used in Flux Skew environment to model the machine can be modified: “Skew model - No. of layers” ( Number of layers for modelling the skewing in Flux Skew environment ).

3.5 Rotor initial position

The initial position of the rotor considered for computation can be set by the user in the field « Rotor initial position » ( Rotor initial position ). The default value is equal to 0.

The range of possible values is [-360, 360].

The rotor initial position has an impact only on the induction curve in the air gap.

3.6 Mesh order

To get the results, the original computation is performed by using a Finite Element Modeling. The geometry of the machine is automatically meshed.

Two levels of meshing can be considered for this finite element calculation: first order and second order.

This parameter influences the accuracy of results and the computation time.

By default, second order mesh is used.

3.7 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 a higher mesh density inside the airgap, increasing the computation accuracy.

The imposed Mesh Point (size of mesh elements touching points of the geometry) is described with the following parameters:

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].

0.05 giving a very high mesh density and 2 giving a very coarse mesh density.

CAUTION:
Be aware, a very high mesh density does not always mean a better result quality.

However, this always leads to a huge number of nodes in the corresponding finite element model. So, it means a need of huge numerical memory and increases the computation time considerably.