An Approach to Predict IPM T-LSMs Air Gap Flux Density: Application to the Mover Geometry Sizing

The paper introduces an analytical approach topredict the no-load flux density spatial repartition of innerpermanent magnet tubular-linear synchronous machines (IPMT-LSMs). It considers a trapezoidal waveform whose maximumvalue is predicted using a simple magnetic equivalent circuitof an elementary part of the machine. Then, the accuracy ofthe proposed approach is enhanced by the incorporation ofa mover permeance function that accounts for the PM luxconcentratingarrangement. Following its validation by a 2Dfinite element analysis (FEA), the proposed approach is appliedto the investigation of the impact of the mover geometry on theair gap flux density with emphasis on the mover pole shoes bydistinguishing the cases of rectangular and trapezoidal shapes.This makes it possible the selection of an IPM T-LSM withappropriate mover geometry for which further investigation ofthe no-load operation is achieved onsidering FEA as well asexperiments carried out on a prototype.