A magnetless or non-rare-earth magnet motor for electric vehicle applications

Abstract

The rise in popularity of the electric car was first started in the year 1859, but it soon ceased to be a viable commercial product near the 1920s, due to the introduction of internal combustion engine (ICE) vehicles. It was not only until recent years that the use of electric cars has been slowly increasing again, due to rising global concerns such as the depletion of fossil fuels or the need to reduce carbon footprints.

Majority of electric vehicle motors currently use rare-earth elements such as Neodymium (Nd) or Samarium (Sm), which are gradually growing in shortage. The prices of these rare-earth elements have increased due to high demand in the industry, and hence, there is a need to come up with alternatives by introducing a magnetless or non-rare-earth magnet (NREM) motor for direct-drive applications, while maintaining the efficiency and torque density of present ICE and rare-earth magnet motors.

This study focuses on the study of ICE and rare-earth magnet motors, while presenting two alternative solutions, namely, an Alnico brushless IPM NREM motor and an induction motor. Analysis of the different motors were simulated using the JMAG software to determine the torque density and efficiency, which were then used to evaluate the performance of the proposed alternative solutions.

At the end of the simulation studies, it was discovered that a 6-pole Alnico brushless IPM NREM motor with an amount of 2.075Nm/kg torque density was a suitable alternative for direct-drive applications. However, it should be noted that a 10-pole brushless IPM REM motor generated much more torque density of 15.98Nm/kg. Despite the Alnico brushless IPM NREM motor being a possible alternative, more research is recommended to further optimize the motor’s design for direct-drive applications.