Generation and rotation of 3-D finite element mesh for skewed rotor induction motors using extrusion technique

A simple method to generate and rotate 3-D finite element meshes for skewed rotor induction motors using extrusion techniques is presented. Special techniques to consider the geometrical structure of skewed rotor bars are described. With the proposed method, a change in the topology of the meshes at different rotor positions needs minor modifications only. The 3-D mesh for the rotor can thus be rotated with minimal extra computing time. Here the 2-D multi-slice mesh is used as the base-planes for extruding the 3-D mesh and the results of the 2-D multi-slice model can thus be used in the 3-D model. The techniques reported in this paper greatly simplifies the 3-D mesh generation, resulting in a considerable reduction in the computing time of the associated 3-D time stepping model. The generated meshes have been used successfully in constructing the 3-D time stepping finite element model for studying the electromagnetic field of induction motors.