Synchronous reluctance motors with toroidal windings

This paper introduces the concept of a four-pole toroidally wound synchronous reluctance machine as an alternative to conventional and fractional slot concentrated winding designs. The toroidal windings, which are wound around the stator coreback have very short end windings, limiting the copper loss as with fractional slot concentrated windings, facilitating an increase in machine efficiency. However, unlike fractional slot concentrated windings, even space-harmonics in the air gap do not exist and the associated parasitic effects are minimized. The machine concept is described and its relationship with conventional and fractional slot concentrated winding machines is discussed. Construction methods are discussed with emphasis on manufacturability and the advantages and disadvantages of this topology are presented.