Defining the Rotor Data for a Three-Phase Induction Motor

The rotor consists of copper bars in which current is induced by the magnetic fields produced by the stator windings. In the project tree, double-click Machine-Rotor, Machine-Rotor-Slot, and Machine-Rotor-Winding to define the rotor slots and vents.

To define general stator data:

  1. To open the Rotor Data Properties window, double-click the Machine>Rotor entry in the project tree on the desktop. (You can also enter values in the Properties section of the desktop without opening a separate window.)
  2. Enter the stacking factor for the rotor core in the Stacking Factor field.
  3. Enter the Number of Slots in the rotor.
  4. Select the Slot Type:
    1. Click the button for the Slot Type.
      The Select Slot Type window appears.
    2. Select a slot type (available types include 1 through 4).
      3. Note: When you place the mouse cursor over the slot type, a schematic of the selected type appears, displaying the slot dimension variables.
    3. Click OK to close the Select Slot Type window and return to the Properties window.
  5. Enter the outer diameter of the rotor in the Outer Diameter field.
  6. Enter the inner diameter of the rotor in the Inner Diameter field.
  7. Enter the length of the rotor core in the Length field.
  8. Select a Steel Type for the rotor core:
    1. Click the button for Steel Type.
      The Select Definition window appears.
    2. Select a steel type from the list, or define a new steel type.
    3. Click OK to close the Select Definition window and return to the Properties window.
  9. Enter the Skew Width, measured in rotor slot pitch. This value defines by how much the rotor bars are skewed.
  10. Optionally, select Cast Rotor to allow the conductor to fill all the space available in the slot. Otherwise, RMxprt assumes the slot wedge that fixes the bars is filled with insulator material in a 2D/3D geometry model.
  11. Optionally, select Half Slot to draw only half of the rotor slots.
  12. Optionally, select Double Cage to specify the winding as a double-squirrel-cage winding.

    13. If you select Double Cage, another line appears in the properties to let you specify the Bottom Slot type.

    1. Click on the Custom button on the Double Cage row. This displays the Select Slot Type window.
      The Select Slot Type window appears.
    2. Select a slot type (available types include 1 through 4).
    Note: When you place the mouse cursor over the slot type, a schematic of the selected type appears, displaying the slot dimension variables.
  13. Click OK to close the Properties window.