Rare-Earth Free EV and HEV Motor Drives: State of the Art

Nowadays, permanent magnet synchronous machine technologies are being widely used in electric and hybrid electric vehicle applications due to their features and high power densities. However and considering rare-earth material cost fluctuations and supply concerns, the manufacturers and academia are working towards the introduction of rare-earth free alternatives. The main drawback of these alternatives is their lower power density. In this context, this paper reviews the recent advances achieved to provide competitive operational features for these alternative candidates, i.e., synchronous reluctance, permanent magnet assisted synchronous reluctance, induction and switched reluctance machines.