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The secondary is an important design factor of single‐sided linear induction motors (SLIMs), as well as has influence on the cost and performance of SLIMs. In this study, the cap‐lamination secondary is designed and relations of the secondary parameter and performance of SLIMs are calculated. First, the aluminium (Al) cap and lamination back iron of the cap‐lamination secondary are designed and discussed. Then, improvements in performance caused by two potentially significant effects of the cap‐lamination secondary, i.e. the thick cap edge and lamination, are identified. Second, a flat‐solid secondary is applied and two SLIMs, which are the same primary and two different secondaries, are calculated by three‐dimensional finite‐element method. Eddy current densities in the Al and back iron plate, which are two parts of the secondary, are analysed. Owing to different transverse edge effects, variations of the air‐gap flux density are calculated with different secondaries. Finally, the numerical results of the thrust, power factor, and efficiency are experimentally validated by measurements on test rig of SLIMs. It shows that the SLIM with cap‐lamination secondary, which has higher performance, is affected greatly by the conductor structure of the secondary and the lamination of the iron back plate. [ABSTRACT FROM AUTHOR]

This study investigates the influence of lateral displacement of the primary on the thrust, vertical and lateral forces in a single‐side linear induction motor for linear metro. A three‐dimensional analytical model, which is able to consider the longitudinal and transversal end effects, overhang of the primary windings and lateral displacement, is developed to obtain the air‐gap flux density distributions along longitudinal and transverse directions as well as forces. Variations of the thrust, vertical and lateral forces with the lateral displacements are comprehensive investigated when the motor is torque motoring, negative sequence braking or regenerative braking operation. The analytically predicted results are experimentally validated by measurements on reciprocal power‐fed test rig. It shows that the thrust and vertical force of single‐side linear induction motor decrease almost linearly with the increase of the lateral displacement in all regions, and lateral force is restoring which helps centralising the railcar in the regenerative braking and most parts of motoring regions. [ABSTRACT FROM AUTHOR]