Design and Analysis of a New Fault-Tolerant Magnetic-Geared Permanent-Magnet Motor

This paper presents a new fault-tolerant magnetic-geared permanent-magnet (PM) motor for direct-drive applications. The key of the proposed motor is to integrate a magnetic gear into a fault-tolerant PM motor, in which the pole-pairs of PMs on both sides of the inner rotor are unequal. Hence, it can incorporate the merits of high torque-to-volume ratio, high gearing ratio, and low-speed high-torque operation with steady speed and high fault tolerance. A new design idea is reported, and electromagnetic performance of the proposed motor is analyzed by using finite element method. Finally, the prototyped motor verifies with theoretical analysis.