Design Considerations of PM Transverse Flux Machines With Soft Magnetic Composite Cores

The design considerations of permanent-magnet transverse flux machines (PMTFMs) with soft magnetic composite (SMC) cores are investigated in this paper. A simplified torque equation of the PMTFMs is deduced first. It is shown that the torque coefficient is directly related to the air-gap flux density, the number of pole pairs, and the stator slot width, etc. To accurately illustrate the influences of these parameters on motor performance, electromagnetic and mechanical analyses are completed by using the 3-D finite element method. For the laboratory prototype, SMC cores can be manufactured by two methods, namely, wire cutting and mould pressing. It is found that wire cutting method deteriorates the magnetic properties of SMC cores and lowers the machine performance. The performance predictions of the PMTFMs are compared for these two methods in this paper. The calculation results are verified by the experimental results.