Fast Computation of Performance Characteristics for Solid-Rotor Induction Motors With Electrically Inhomogeneous Rotors

Design routines for solid-rotor induction motors are usually based on two-dimensional finite element models. It is well known that these models take only approximate account of the rotor-end effect using a reduced value of physical conductivity, called the effective conductivity. Accurate estimation of the latter for machines with electrically inhomogeneous rotors is very difficult, though crucial for the correct prediction of performance characteristics and rotor losses. This paper shows that a previously proposed procedure for numerical estimation of the effective conductivity with a two-dimensional time-harmonic field-circuit finite element model can be effectively used for the fast computation of performance characteristics for solid-rotor induction motors with inhomogeneous rotors. Solid rotors of different construction are investigated to provide deep insight into the rotor-end effect and its influence on the machine performance. The results of this computation are validated experimentally.