Influence of soft magnetic materials on the design and performance of tubular permanent magnet machines

The paper investigates the influence the choice of soft magnetic material on the performance of a tubular permanent magnet machine. The study is based on the design conditions and considers three soft magnetic materials, viz, Transil300, a 3.5% silicon iron lamination material, and the SMC materials Somaloy/spl trade/ 500 and Somaloy/spl trade/ 700. The tubular permanent magnet machine has a modular stator winding and employs a quasi-Halbach magnetized moving armature. The machine design which employs silicon iron laminations has the highest force capability and the best performance, despite its poorer space utilization. SMC machine designs, on the other hand, have an advantage in terms of ease of manufacture.