Polyphase Induction Machine with Deep Ferromagnetic Bar Rotor

The performance of the induction machine with a rotor of ferromagnetic bar assembly presents an interesting field problem not attempted so far. The insulation between the bars introduces an additional reluctance to the magnetic circuit in the circumferential direction and, for a proper theoretical analysis of the problem, the magnetization characteristics of the rotor material have to be modified, resulting in different working permeabilities for the rotor in the radial and circumferential directions. Further restriction on circumferential currents is also imposed by the radial insulation.