A new Halbach arc permanent magnet synchronous motor with three-dimensions air gap used on large telescope

This paper proposes a new arc permanent magnet synchronous motor (APMSM) with three-dimensions (3-D) air gap. The proposed APMSM includes one rotor and four segmental stators which cores and windings are type "C". A 3-D air gap, which is formed by C-type stator and rotor, provides a large air gap area which makes APMSM have higher torque density than that of 2-D conventional arc motor. Halbach permanent magnet (PM), which can reduce torque ripple, is disposed in rotor. The proposed and another two APMSMs are analyzed by finite element method. The characteristics of proposed APMSM, high torque density and low torque ripple, are verified by the computed results.