A Novel Doubly Salient Flux Modulation PM Machine with Halbach Magnets

Abstract

With the advent of high performance permanent magnet materials, many novel PM machine topologies have been developed for various applications. Apart from the “rotor-PM” machines, such as surface mounted, inset and interior PM machines, the “stator-PM” machines [1] such as flux switching (FS-), flux reversal (FS-) and doubly salient (DS-) PM machines have attracted much attention in recent years. With the merit of high torque density, the PM vernier (PMV) machine [2], as a kind of “rotor-PM” machine, has been discussed extensively. Since the PMV machine and magnetic geared machine share the same operation principle [3], they can be classified into the flux modulation machines [4], and the FSPM, DSPM, FRPM and transverse flux PM machines are also included. Based on the flux modulation effect, machines with magnets in both stator and rotor have been the research hotspot recently [5], [6]. In this paper, a novel flux modulation PM machine with Halbach magnets in both stator and rotor is proposed. It’s shown that the torque density of the machine is 49.7 kNm$/ \mathrm {m}^{3}$, more than 1.6 times as that of PMV machines, when the heat loading is $1704 \mathrm {A}^{2} /$cm.mm 2.