A novel axial-flux-complementary doubly salient machine with boosted PM utilization for cost-effective direct-drive applications

Abstract

This paper proposes a novel axial-flux-complementary doubly salient machine (AFC-DSM) for cost-effective direct-drive applications. The key is to coordinate two complementary rotors with inset stator permanent magnets (PMs) circumferentially magnetized to construct an axially complementary flux return path in machine. Different from the traditional stator-PM machines, the excitation flux is transferred between the complementary rotors, hence switched smoothly without been shorted or opened in the air gaps. As a result, the PM utilization in the proposed machine can be doubled compared to that in traditional stator PM machine. In addition, the proposed machine also contributes to reduced cogging torque, higher winding utilization factor and neglectable mutual inductance, which helps to improve its torque performance as well as fault-tolerant capability. The electromagnetic performance is evaluated by 3-D finite element analysis, and the simulation results verify the effectiveness of the proposed machine.