Torques and forces on a moving coil due to eddy currents

Publisher Website
Google Scholar
Abstract
The steady-state forces and torques acting on a planar current-carrying winding, moving at constant velocity parallel to a conducting permeable slab of finite thickness and infinite extent are calculated from exact solutions of Maxwell's equations. These calculations are extended to apply to an arbitrary coil consisting of a superposition of planar windings. The special cases of solenoidal coils of finite and infinite height are discussed as approximations to bar, iron core, and horseshoe magnets, and the limiting cases of magnetic monopoles and dipoles are considered. The relativistically exact formulas are simplified for the practical case of a magnetically suspended train, and similarity laws are derived relating the forces measured on scaled-down models to those on their prototypes. These calculations are valid for levitation over nonpermeable conducting media as well as for the reduction due to eddy currents of the attractive force in the alternatively proposed ferromagnetic suspension systems. Aside from the infinite length and width of the track, the only physical approximations made consist in linearity assumptions in the track: constancy of the permeability and conductivity (Ohm's law).

This publication has 4 references indexed in Scilit: