Influence of Armature Windings Pole Numbers on Performances of Linear Permanent-Magnet Vernier Machines

Linear permanent-magnet vernier (LPMV) machine has attracted more and more attention for several advantages including high power density and low cost. Both magnets and windings are located on the short mover, while the long stator is only consisting of iron, which is very suitable for long stroke applications. This paper investigates the influence of armature windings pole-pair numbers on the electromagnetic performances of LPMV machine by using an analytical method based on the finite element. The aim of this paper is to make a comprehensive comparative study of the machine with different armature windings pole-pair numbers while keeping slot number as a constant, select the topology of high performances and recommend suitable application areas. The performances of machines with the armature windings pole-pair numbers Pw= 1, 3, 6 are analyzed in detail. Finally, a new modular LPMV machine with Pw= 6, which possess higher thrust force, lower thrust force ripple, and high fault-tolerant capability, is prototyped and experiments are conducted for validation.