Magnetic circuit analysis and performance improvement of a tubular staggered-tooth transverse-flux linear machine for free-piston energy converter

A free-piston energy converter (FPEC) integrated by a combustion engine and a linear electric machine is suitable for series HEV or other applications stand-alone generators. The transverse-flux machine (TFM) is considered advantageous for such application because of its high specific power and force density [1]. The finite element method (FEM) is widely used in the machine analysis, which is time-consuming. The equivalent magnetic circuit analysis is a time-effective method compared with FEM.