Minimization of Outlet Edge Force Using Stair Shape Auxiliary Teeth in a Stationary Discontinuous Armature Linear Permanent Magnet Motor

Abstract

The stationary discontinuous armatures that are used in permanent magnet linear synchronous motors (PM-LSMs) have been proposed as a driving source for transportation systems. However, the stationary discontinuous armature PM-LSM contains the outlet edges which always exist as a result of the discontinuous arrangement of the armature. For this reason, the high alteration of the outlet edge cogging force produced between the armature's core and the mover's permanent magnet when a mover passes the boundary between the armature's installation part and non-installation part has been indicated as a problem. Therefore, we have examined the outlet edge cogging force by installing the stair-shaped auxiliary teeth at the armature's outlet edge in order to minimize the outlet edge cogging force generated when the armature is arranged discontinuously. This paper presents the results of 2-D numerical analysis by FEM of the cogging force exerted by the outlet edge.