Investigation of Dual-Sided Consequent-Pole Flux-Modulated Permanent-Magnet Machine by Air-Gap Field Modulation Theory

Abstract

High torque density permanent-magnet (PM) machines have become an increasingly critical requirement for drive systems. Traditional PM machines face significant challenges in achieving higher torque densities due to limitations imposed by electrical loading and heat dissipation conditions. In this article, a novel dual-sided consequent-pole flux-modulated PM machine (DCFPM) is proposed and compared. Both stator and rotor are adopted with consequent-pole PM arrangement to enhance modulation effect and improve torque density. Based on the air-gap field modulation theory, the topology, operating principle, and flux modulation effect of the proposed DCFPM are analyzed. The electromagnetic performances, including EMF, torque characteristics, PM utilization ratio, and power factor, are evaluated by finite element analysis. The results show that the bidirectional flux modulation in the proposed DCFPM is beneficial to enhancing flux densities and torque production capability. Finally, the discussions and conclusions about different PM machines are carried out; it can be concluded that the proposed machine with 12-slot/34-pole/12-modulation pole can offer merits of high torque density, high power factor, and excellent overload capability.