Prediction of thrust forces in tubular induction machines

Modular airgap windings for linear permanent magnet machines

“…The prediction of the performance of an induction machine's magnetic circuit by considering it to be formed by a series of infinite layers of material energised by MMF sources, and solved by analogy to transmission lines, has been well reported [11][12][13][14][15]. This method considers the machine to be formed from an idealised structure comprising a number of laminar regions parallel to the airgap and of finite extent in the plane of lamination and of arbitrary thickness.…”

“…The phase sequence sets for the 12-coil winding can be deduced by using the same procedure as in the Appendix (13). Forward and backward sets occur at the same harmonic numbers except that all even harmonics have been shown to be zero.…”

“…N sa e − jpW sa 2π /L = N pa e jφ pa (12) Similarly, distribution of b phase and c phase can be expressed as N pb = N pb e jφ pb and N pc = N pc e jφ pc (13) The winding distributions of a three-phase winding may be represented by positive, negative, and zero phase sequence sets each having three balanced windings. The amplitude and position of the first winding in each set for the pth harmonic is given by:…”

Tubular Linear Induction Machine as a Fast Actuator: Analysis and Design Criteria

“…More accurate design requires the development of 3D models of the motors that allow to determine the distribution of electrical and mechanical quantities taking into account the finite length of the machine, the presence of slots and teeth, the presence of nonlinear materials and the transient nature of the phenomena that take place in these devices [10][11][12][13][14][15][16][17][18][19]. Numerical method based on integral formulation may be convenient in the analysis of such devices because of the presence of conductors in motion.…”