Finite element analysis of end ring impedance in squirrel cage induction machines

In squirrel cage rotors of induction machines with unconventional end region structure, the three-dimensional effects can be more pronounced as compared to conventional induction machines. As a result, the rotor impedance and machine power factor are affected by the design of the end ring and its supporting structure. To be able to account for this effect, three-dimensional finite element (3D FE) analysis is required. In this paper, the steady state 3D FE analyses are employed to identify the equivalent circuit parameters. Further, the internal power factor and the rotor bar and end ring impedances are investigated. It is further presented how the findings of the 3D FE study can be implemented in two-dimensional (2D) FE model in the distributed circuit.