Comparison of five topologies rotor permanent magnet motors with improved fault-tolerance

This paper presents a detailed comparison of five topologies for rotor permanent magnet (RPM) motors with improved fault-tolerance. The five topologies include one surface-mounted topology, one surface-insert topology and three interior topologies (spoke-type, conventional and V shape). In these motors, the fault-tolerant teeth (FTT) and the concentrated winding are adopted to offer the merit of phase decoupling, which can make these motors offer the fault-tolerance. The performance characteristics, which include the flux density of air-gap, back electromotive force (back-EMF) and its harmonics, magnet mass and cogging torque are compared and analyzed. These electromagnetic characteristics of these proposed motors are analyzed by using the time-stepping finite-element method (FEM). The aim of the paper is to give some guidance and references for RPM motor designers.