Permanent magnet assisted synchronous reluctance motor: Analysis and design with rare earth free hybrid magnets

Abstract

The traction machine is one of the prime components of electric vehicles. Due to the high power density and efficiency, permanent magnet machines are largely preferred for traction. In this paper, the usage of hybrid rare earth-free magnet materials (Alnico and Ferrite) in a 1.5 kW synchronous reluctance machine are studied and compared with the conventional permanent magnet assisted synchronous reluctance machine. The no-load characteristics like air gap flux and back EMF are analyzed initially and the dynamic performances are discussed later. The simulation results show that the usage of hybrid magnet materials helps to reduce the active material requirement by 24% over the conventional ferrite magnets. Compared to conventional machines, the field weakening can be improved effectively by preferring hybrid magnets and the active material cost can be reduced by 29%.