Design of a Double-Stator Hybrid Flux Switching Permanent Magnet Machine for Direct-Drive Robotics

Direct-drive robotics is quite attractive because of its high efficiency, high robustness and wide application prospect. This paper is to propose a new double-stator hybrid flux switching permanent magnet (DSH-FSPM) machine for the direct-drive robotic applications. The key is to integrate the distinct merits of high torque density, flux-modulation capability, high fault-tolerant capacity and low torque ripple together. First, the machine design and flux switching principle are analyzed to illuminate the basic operation principle. Also the machine performance shows that the inner and outer torque ripples offset with each other and contribute to the low torque ripple less than 7%. Furthermore, with the addition of the DC current, the machine flux and EMF can be weakened, which can enlarge the flexibility and stability for the machine operation. The performances of the machine verify the feasibility of the new topology for the direct-drive robotics.