Design of External Rotor Ferrite-Assisted Synchronous Reluctance Motor for High Power Density

The rare-earth (RE) permanent magnets (PM) have been increasingly adopted in traction motor application. However, the RE PM is expensive, less abundant, and has cost uncertainties due to limited market suppliers. This paper presents a new design of RE-free five-phase ferrite magnet-assisted synchronous reluctance (Fe-PMaSynRM) with external rotor architecture high saliency ratio. In such architecture, low magnetic coercivity demagnetization risk challenge. limits number flux barriers, ratio, torque. A precise analytical procedure stator configuration presented differential evolution numerical optimizations by utilizing lumped parameter model. 3.7 kW prototype fabricated validate proposed idea.