Electromagnetic performances analysis of flux-intensifying permanent magnet synchronous machine with modular fractional slot concentrated windings

This paper proposes a topology of 3-phase 9-slot/10-pole flux-intensifying permanent magnet synchronous motor (FI-PMSM), which provides distinct merits over conventional PMSMs. By adopting the modular fractional slot concentrated windings, the cogging torque of the proposed motor can be suppressed effectively. Furthermore, due to larger d-axis inductance L_d than q-axis inductance L_q, positive d-axis current I_d can be used under loaded conditions to prevent magnet demagnetization and produce positive reluctance torque at the same time. By finite element analysis, the proposed motor shows advantages in improving efficiency and speed range in the low torque region.