Design Optimization and Performance Investigation of Novel Double-slit Secondaries for Linear Induction Motors

In order to reduce the end effect of linear induction motors for low-speed Maglev train, this paper proposes a kind single-sided linear induction motors (SLIMs) with novel double-slit secondaries, which include symmetry, asymmetry and V-shaped three types. Firstly, the 3-D finite element models are built for the proposed SLIMs and normal SLIM with cap-solid secondary respectively. Secondly, for the proposed SLIM, the topology parameters are investigated by the single-variable optimization method, including the width of secondary side-bars, transverse depth of secondary slots, secondary slots width, the stagger distance between two slits of asymmetry type and the skew angle of V-shaped type. Finally, the air gap flux density, eddy current, thrust force and normal force of the proposed SLIMs with double-slit secondaries are compared with those of traditional SLIMs with cap-solid secondaries. The results show that the proposed SLIMs, especially with V-shaped secondaries, can not only reduce the transverse end effect, but also improve the force performance.