Research of a core-less linear machine with applied Halbach array for low speed application

Abstract

PurposeThis paper aims to present a Halbach magnet array linear machine, without an iron core and the electromotive force (EMF) characteristic results.Design/methodology/approachThe linear machine was made with mover coils and a permanent magnet stator without an iron core. For an outline design, the analyzed magnetic density results were compared to the Halbach array with a horizontal array using the 3D finite element analysis. The test was carried out on an experimental system using a prototype linear machine. The EMF of the linear machine, with applied Halbach array magnetic circuit, is verified with the experiment.FindingsThe EMF peak value of the Halbach array is larger than the EMF of the horizontal array. Compared to the EMF in the experimental results, the effective value of the Halbach array is 1.69 times greater at an average operation speed of 373 mm/s.Originality/valueThe core-less linear machine has advantages of reduced cogging torque and iron loss because both the stator and the mover do not have an iron core. The stator and rotor will not rust from water. In this paper, it is clear from the basic electrical characteristics that the linear machine, with applied Halbach array, is larger than the EMF of the horizontal array.