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

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.