Primary component segmental design to suppress the normal force ripple for the permanent magnet linear synchronous motor

There is not only thrust but also normal force between the primary and secondary components for the single-side flat plate permanent magnet linear synchronous motor (PMLSM). The normal force will fluctuate periodically, which will cause friction perturbation and finally affect the positioning accuracy of linear feed system. For the single-side flat plate PMLSM, the variation law of normal force ripple under the coupling effect of multiple effects is studied, and the method of primary component segmental design to suppress it is proposed. Firstly, the influence of the cogging effect, the end effect and the armature reaction on the normal force ripple is analysed. Meanwhile the mathematical model of normal force ripple is established. Secondly, the PMLSM with segmental primary component is introduced and its suppression mechanism to the normal force ripple is expounded. On this basis, a scheme combining the non-integer pole slot matching with the primary component segmental design is proposed to further suppress the normal force ripple. Finally, an 18-slot 96/5-pole prototype is taken as an example to carry out the finite element simulation and experimental test, of which the results verify the research theory in this paper.