Design of a Novel Dual-Rotor Permanent Magnet Multiport Machine with C-Type Stator

a novel dual-rotor permanent magnet multiport machine with C-type stator is proposed in this paper. The key point of this proposed machine is using the C-type stator to separate the magnetic and electric load. It is contributed to decrease the air-gap length to improve the torque density. For the conventional multiport machine, the main flux path flows across six-layer air-gaps because of the dual-rotor, dual stator structures. Compared with the conventional multiport machine, the proposed machine with C-type stator just across three-layer air-gaps. Moreover, the outer and inner rotor of the proposed machine rotates based on flux field modulation principle at the contra-rotating speed to generate the high frequency air-gap flux field. In this paper, the overall structure of this machine is first introduced. Second, the flux field modulation principle in dual-rotor structure and the flux circuit in C-type stator is analyzed. Finally, the prototype of the proposed machine is selected and compares with the conventional dual-rotor permanent magnet multiport machine through finite element analysis method.