Joints in strips for electrodynamic magnetic levitation systems

The force disturbances experienced by the superconducting magnets of an electrodynamically levitated vehicle due to guideway strip thermal expansion joints are studied. The experimental investigation covers the low, intermediate, and high speed ranges, and it is shown that the change in eddy current distribution at a guideway strip discontinuity, i.e., at a simple butt joint, can cause severe transients in the electrodynamic forces. A number of possible joint configurations are examined, and it is shown that the use of an overlap joint or a backing/covering strip can reduce transients to an acceptable level.