Performance comparison between different rotor configurations of PMSM for EV application

Abstract

The modern world is concerned about the coal reserves, hiking prices of petroleum products, air pollution, and global warming. These all create a great demand for Electric Vehicles (EV). The government authorities have already initiated several projects which targeted on sales of millions of EVs by 2025. Electric three wheelers (E-rickshaw) have a high demand in a country like India since it's a common mode of transportation. Different types of AC and DC motors are used in EV, among them Permanent Magnet Synchronous Motor (PMSM) posses high efficiency due to its high power density, small size, great torque inertia ratio, better overload capacity, high output torque, and fewer losses. The torque, efficiency and power density of PMSM is dependent upon its rotor configuration. The paper discusses detailed design of PMSM with different rotor configurations, especially concentrating on the design and calculation of air gap length and permanent magnet dimensions. The designed values are further used for the virtual development of PMSM on ANSYS MAXWELL platform, considering seven different rotor topologies like surface- mounted, de-centred PM, spoke type, interior PM, U-shaped, V-shaped, modified V-shaped. A detailed comparative study based on performance characteristics like weight, cogging torque, power, efficiency, air gap flux density, magnetic flux density, etc. obtained from the Maxwell platform was done. The paper concludes by the selection of modified V-shaped rotor topology of PMSM. It is most efficient and chosen for the electric vehicle (E- rickshaw) application.