An approach to generate high reluctance torque in an inset-type PMSM by square current excitation

This paper describes an approach of an inset-type permanent magnet synchronous motor (PMSM) to achieve a high reluctance torque by using a square current excitation. The square waveform of the three phase bipolar current contains a lot of harmonic components. The motor with available to the harmonics has a potential to realize higher torque in comparison with the torque of another AC machine with the sinusoidal excitation scheme. We investigate a novel inset-type PMSM which is called the inset magnet-type reluctance motor (IMRM). This paper compares the output torque of three types of PMSM (inset-type, surface-type and interior-type) under the condition of equal current RMS condition by the using theoretical calculation and the finite element analysis (FEA). The results show that the novel concept machine achieves higher torque than the same size of surface-type PMSM (SPMSM) and interior-type PMSM (IPMSM).