Experiment and Simulation of REBCO Conductor Coils for an HTS Linear Synchronous Motor

A high temperature superconducting (HTS) linear synchronous motor that uses REBCO-coated conductor as the secondary excitation system was recently demonstrated. Four series-connected REBCO-coated conductor coils were fabricated via the epoxy impregnation technique and the critical current of each coil can be retained by a percent of over 75% at 77 K after winding. Meanwhile, a three-dimensional (3-D) finite-element model was established to describe the coated superconductor coils subject to the traveling magnetic fields of a conventional copper-based stator. The comparison between experiment and simulation in terms of thrust has verified the developed 3-D numerical model, allowing the complex studies of HTS linear motor prior to fabrication. Our preliminary testing has shown that, when the coated superconductor coils were placed over a three-phase stator, the transport dc current in the coated conductor coils will exhibit a significant variation, depending on its magnitude and the operating frequency of stator current as well as the electromagnetic gap.