Experience of Toroidally Wound Double Rotor Axial-Gap Induction Machine With Soft Magnetic Composites

In this paper, a double axial gap type induction motor having a toroidal winding stator structure is proposed for the purpose of improving the torque density and efficiency of the induction machine. It consists of an axial type squirrel-cage induction rotor, and a toroidal winding stator structure suitable for armature copper loss reduction, miniaturization and a double axial gap structure. After explaining the reasons for selecting the single stator and double rotor structures, the structural design of the prototype and the experimental setup will be reported. The slip- vs .-torque characteristics are measured to clarify the drive characteristics, and the features of the proposed motor used soft magnetic composites are discussed by the equivalent circuit method. As a result, it was experimentally clarified that the double axial gap type induction motor with soft magnetic composites has a high slip torque characteristic and the reduction of the excitation current is an important issue for improving the performance.