Analytical Modeling and Experimental Verification for Electromagnetic Analysis of Tubular Linear Synchronous Machines With Axially Magnetized Permanent Magnets and Flux-Passing Iron Poles

This paper presents the analytical modeling and experimental study for electromagnetic analysis of tubular linear synchronous machines with axially magnetized permanent magnets, accounting for the flux-passing iron pole. The field domains are divided into five regions: air gap (I, III), coreless winding (II), outer magnet mover (i), and nonmagnetic material (IV). The governing equation in all subdomains can be solved, and the field distribution can be obtained by applying the boundary conditions to the interfaces between the subdomains. The analytical solutions allow for the prediction of the back electromotive force, inductance, and generating characteristics in closed forms. The magnetic field and electromagnetic performance obtained by the analytical method were compared with those obtained by the finite element method and experimental test. In turn, these facilitate the characterization of the machines and provide a basis for comparative studies, design optimization, system dynamic modeling and simulations, and control development.