Design and Analysis of IPMSM with Modular Stator Structure for Electric Vehicular Applications

Traditionally, interior permanent magnet synchronous machines (IPMSMs) with non-modular stator structures are widely used in electric vehicles (EVs) owing to higher power and torque density. However, it occupies more space, less efficient and unable to operate under phase faults. To address the aforementioned concerns, this paper introduces IPMSMs with a modular stator structure for EV applications. The proposed stator structure improves electromagnetic torque and efficiency of IPMSM. To validate these features, modular IPMSMs with different slot/pole combinations (12-slot/10-pole and 12-slot/14-pole) consisting of flux-gaps in alternate stator teeth and single-layer concentrated winding is investigated. As a result, it enhances the slot filling factor, output torque and power density. To find the suitability of these machines, a 2-D finite element (FE) analysis is carried out using Ansys-Maxwell software. The performance of these machines is holistically evaluated in terms of phase back-EMF, on-load torque, torque ripple, core losses, copper losses, and efficiency by varying the slot/pole number and flux-gap widths. Finally, the performance of these modular IPMSMs is compared with that of non-modular IPMSMs.