A 3-D analytical model for a double Halbach linear array electrodynamic suspension system

By translationally moving a magnetic source above a conductive plate guideway both levitation and drag forces are created. Unfortunately, the electrodynamic drag force can be quite high [1]. Kratz studied a double Halbach array topology, such as shown in Fig 1 [1], and used a simple curve fitting approximation to model the forces. Kratz experimentally showed that a significant reduction in drag force can be created when using this “null current” approach. Much earlier Urankar derived analytic equations for a similar double coil system [2].