Wound Field Synchronous Motor Using a Non-Salient Pole Rotor with Distributed Winding

The growing demand for electric vehicles (EVs) has led to an increased requirement of high-performance, efficient, and reliable electric traction motors. These motors use permanent magnets that contain dysprosium/terbium, leading to its scarcity and increased cost. Anticipating this problem, some alternative motors that do not use these rare earth metals are being developed. One such rare earth metal-free motor is the wound field synchronous motor (WFSM), which has gained attention in both academia and industry. One of the exciting features of the WFSM is the control of the rotor magnetic flux, which can improve motor efficiency at high speeds. This study presents a WFSM comprising a non-salient pole rotor with distributed winding for use as a traction motor. Different variations of the motor design were studied for high torque density and efficiency, and the electromagnetic performance of the motor was analyzed via numerical simulations. The results demonstrate that the proposed WFSM can provide high efficiency in low torque regions and be used as a traction motor.

I. Introduction

Increasing concern regarding climate change and pollution has forced the automotive industry and policymakers to adopt sustainable development. The demand for battery electric vehicles (BEVs), including hybrid electric vehicles, has grown rapidly considering net zero carbon emission technology demand Additionally, by 2035, EVs are estimated to comprise approximately half of new car sales worldwide [1]. This has increased the demand for high-performance, efficient, and reliable electric traction motors. The common types of electric motors used as traction motors include induction motors and permanent magnet synchronous motors. Specifically, interior permanent magnet synchronous motors (IPMSMs) are widely used because of their wide speed range and field-weakening control.