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Since the linear induction motor commonly work with a laterally asymmetric secondary as it is applied to pull rail vehicles, this paper presents a complete equivalent circuit model considering the asymmetry to predict thrust, vertical and transversal forces. First, six correction factors are presented to quantify the variations in the air-gap magnetic flux and secondary induced current as the linear induction motor operating with a laterally asymmetric secondary. Second, it develops a circuit model based on the existing T-model for the rotary induction motor and two correction factors for the magnetizing branch, which is used to indicate the electromagnetic variations in the air-gap flux and secondary plate due to the asymmetry. Third, the mathematical expressions for the thrust, vertical and transversal forces are derived by applying the equivalent circuit model. Then, the six correction factors are calculated with a prototype motor, and the results of them are comprehensively analyzed. Finally, the characteristics in the prototype motor are calculated with the mathematical expressions in a range of rated speed, and validated by the experimental measurements carried out on a test rig and line for linear motors. [ABSTRACT FROM AUTHOR]

Since single-sided linear induction motors working with a lateral asymmetric cap secondary is a frequent operating condition, this paper develops an equivalent circuit model considering the asymmetric condition. First, an analysis model, which takes the longitudinal end effect and skin effect into consideration, is proposed. Second, a transversal analysis model considering the laterally asymmetric cap secondary is developed to derive its correction factors. Then, the influence of lamination eddy current on the effective air gap to transversely directed flux is contrastively analyzed. Third, the traction characteristics of a prototype motor with symmetric and asymmetric cap secondary are calculated by the equivalent circuit. Finally, these calculated results are verified by measurements carried out by a test rig of the linear motor. [ABSTRACT FROM AUTHOR]