A Novel Spoke-Type IPM Rotor With Hybrid Radial and Axial Flux Concentration for Reduction of Interpolar Leakage Flux

Axial leakage magnetic flux is generated in the spoke-type interior permanent magnet synchronous motor (IPMSM) because of the flux-concentrating rotor structure, which degrades the performance of the motor. In this article, a traditional spoke-type interior permanent magnet (IPM) motor is fabricated and tested first. Then a novel spoke-type IPM rotor with hybrid radial and axial flux-concentrating capability is proposed to reduce the interpolar leakage flux and improve the torque performance. Furthermore, the radially magnetized PMs are installed in the inner circumference of the rotor, which can reduce the rotor-interior flux leakage. Finally, the superiority of the two proposed structures is verified through three-dimensional finite-element analysis (3-D FEA).