Permanent-magnet linear eddy-current brake with a nonmagnetic reaction plate

A new two-dimensional analytical model is presented for a double-sided permanent-magnet brake with a nonmagnetic reaction plate, based on an equivalent volume current representation of the permanent magnets. An exact solution of the field equations for an infinitely long machine, together with an approximate treatment of end effects, leads to simple expressions for the braking and normal forces as functions of the secondary plate speed. These expressions clearly show the effects of the brake geometric parameters and the plate conductivity on the performance. The model has been validated by experimental measurement of the braking force as a function of speed, and by finite-element calculation of the flux density and normal force at standstill