Design of Soft Magnetic Composite based modular four phase SRM for electric vehicle application

A modular 4 phase Switched Reluctance Motor (SRM) for an electric two wheeler is designed. Conventional 4 phase SRM suffers from low frequency torque ripple due to asymmetric mutual coupling between adjacent phases. Therefore, a modular stator and rotor structure is proposed which eliminates mutual coupling between adjacent SRM phases. Since the structure needs 3D flux capability, Soft Magnetic Composite (SMC) material is utilized for this motor. The 3D-FEA based design of individual stator and rotor parts is given and comparative study is carried out with conventional 4 phase tooth type SRM of same outer dimensions. The modular structures also eliminated the flux reversals in the SRM reducing the core loss. Therefore, the modular SRM is able to achieve comparable efficiency to that of conventional SRM while the manufacturing cost is significantly reduced due to the modular structure.