Comparison of traction motors that reduce or eliminate rare-earth materials

Important global efforts are underway toward lowering the cost of electric machines for electric and hybrid vehicles by reducing or eliminating the use of rare earth materials which have been experiencing significant price increases and volatility. This paper will present several designs that reduce or eliminate rare-earth materials. All these designs are targeting the same set of specifications of 55kW peak at 2800 rpm and 30kW continuous over a speed range going from 2800 rpm to 14000 rpm. This provides a fair basis of comparison of various machine topologies. The paper will provide a quantitative comparison of the performance of various machine topologies as well as highlight the key tradeoffs.