Effects of Axial Slits on the Performance of Induction Machines with Solid Iron Rotors

The paper deals with the improvement in the performance of an induction machine with a solid iron rotor slitted axially. The improvement is observed mainly in the full-load slip, the power factor, and the starting torque. In this paper, a one- dimensional model of a slitted rotor is presented based on the original and novel concept that the tooth and slit profile is a flux line. Based on this, the field distribution inside the iron is obtained from 1) a linear theory and 2) a limiting nonlinear theory. The results of the analyses based on these theories are found in better agreement than those based on the composite permeability theory.