The performance of induction levitators

Induction levitators are devices which produce repulsion as a result of the interaction between excited coils and the eddy currents which they induce in some other conducting member. Machines such as this have been proposed as the levitation mechanism for contactless transport systems (MAGLEV)[1,2], or as magnetic bearings [3]. In this paper we present studies of small laboratory models of induction levitators (Fig 1). Measurements are compared with calculated values obtained by a finite element analysis. The secondary consists of a conducting plate which could be backed by iron if required, and detailed measurements and calculations are presented which illustrate the effects of the shape and size of the secondary on the forces (lift and lateral) and the power factor. A levitation system for a 50 tonne MAGLEV vehicle is then investigated computationally.