Quantitative comparison of low-cost electrical machines with soft magnetic composite and ferrite magnet materials

Because of its special structure and manufacturing process, the soft magnetic composite (SMC) material has shown its advantages over silicon sheets, including magnetic and thermal isotropy, low high-frequency core loss, low material wastes during its manufacturing process, etc... Considering the price of SMC raw material can be very cheap in the future, it is an ideal material for developing the low-cost electrical machine. Combined with SMC cores and low-cost ferrite magnets, some electrical machines with SMC and ferrite magnets for low-cost applications were developed in the past decades, which include the transverse flux flux switched permanent magnet motor (TFFSPMM), axial flux claw pole permanent magnet motor (AFCPM), axial flux vernier motor (AFVM), dual rotor axial flux permanent magnet motor (DRAFM) and axial radial flux permanent magnet motor (RAFM). To better utilize SMC material, all these machines are designed following the design guidelines of SMC machines. Though both of them with good performance for low-cost applications, it is necessary to know the main advantages of each machine. The main target of this paper is to compare these machines quantitatively. For obtaining the comparison results fairly all these machines are optimized by using the sequential robust Taguchi method. Finally, it can be seen that the AFVM and TFFSPMM are with relatively high torque ability and the DRAFM is with high efficiency and power factor ability.