Structural design and performance prediction of novel modular tubular permanent magnet linear synchronous motor

The limitation of the primary core length of the tubular permanent magnet synchronous linear motor (TPMSLM) causes large thrust ripples during operation. To end this, a modular TPMSLM with two units is proposed. The principle of its suppression of end effects is derived, and utilization of the three-phase winding is improved using the star vectograms of the back electromotive force (EMF). Afterward, an equivalent subdomain method is adopted to analyze the above structure. This method combines the subdomain and the equivalent magnetic circuit (EMC) model, and the comparison with nonlinear FEM verifies its effectiveness. Using this integrated approach, reasonable structure parameters are selected. Finally, the experimental platform of the two-unit modular TPMSLM prototype is built with the selected structural parameters. Good agreement between the simulation and the experiment on the back EMF, detent force, and the prototype's static thrust verifies the new structure's feasibility.