A new viewpoint of end effect of linear induction motor from secondary side in ladder type model

As a new viewpoint, the physical phenomenon of end effect in a ladder type linear induction motor (LIM) is observed from the secondary side by making use of the structural feature. The phenomena in the ladder type and the sheet type LIM are the same fundamentally. The analytical method for the study is the special two-dimensional electromagnetic analysis, in which the current in each conducting bar is determined considering the time harmonics of the secondary current. A new factor tp/ts is proposed to present the degree of end effect, in which tp is the passing duration of the primary core at a secondary point and ts the half-period of the slip frequency.