A Novel Five-Phase Double-Stator Tubular Fault-Tolerant Flux-Modulation Permanent Magnet Motor

Tubular permanent magnet motors have been applied to many direct drive systems. This paper proposes a novel double-stator tubular fault-tolerant flux-modulation permanent magnet motor for an electromagnetic suspension system. The key of the proposed motor is the special double-stator and flux-modulation structure. The double-stator structure can make best use of the inner space of the motor. The flux-modulation structure is based on the magnetic gear effect, which can use effective harmonic components of magnetic field. Thus, the thrust force density is improved. Additionally, the idea of single-layer fractional-slot concentrated windings and fault-tolerant teeth is used to enhance fault-tolerant capability. The electromagnetic performance is analyzed by using the time-stepping finite-element method, verifying the effectiveness of the theoretical analysis.