Comparative Study of Transverse Flux Permanent Magnet Machines for Wind Power Applications

In this paper, the optimal designs of a surface-mounted permanent magnet (SPM) machine and various topologies of the transverse flux permanent magnet (TFPM) machine are comprehensively investigated and compared at 3 kW and 3 MW power levels. The 3 MW SPM machine surpasses all TFPM machine topologies in terms of power factor, efficiency, torque/mass and torque/cost ratios except for torque production capability. The highest torque achieved by the surface-mounted TFPM (SMTFPM) machine is 5.9% greater than that of the SPM machine. On the other side, 3 kW TFPM machines perform comparably better than the 3 MW TFPM machines due to less flux leakage and magnetic saturation with lower electrical loading. However, the highest torque from the 3 kW SMTFPM machine with iron bridges among all TFPM machine configurations still has 2.1% lower torque than the SPM machine, although it has higher torque/mass and torque/cost ratios than the 3 kW SPM machine.