Design and Key Performance of 2G HTS Coils for High Speed Superconducting Maglev Application

Abstract

Superconducting material can be utilized into linear synchronous motors (LSMs) in magnetically levitated maglev trains, considering its high current density without generating any Joule loss. The development of second-generation (2G) high-temperature superconducting (HTS) tapes simplifies design of superconducting coils as its operating temperature can be raised up to 40 K. In the scheme of HTS coils, evaluation of critical current (I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c0</sub> ), which can be modeled based on finite element method using Maxwell's equation, is a crucial part. In this paper, the prototype of HTS coils is designed and optimized which will be further applied to a linear propulsion system. In view of a conduction cooling method, each magnet pole is composed of two coil modules. Two double racetrack coils wounded by REBCO tapes build up one coil module. Its critical current is figured and compared in liquid nitrogen temperature (i.e., 77 K) by experiments as well as simulations, based on H- and T-A formulation. Performance of I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c0</sub> at 30 K and 40 K are also estimated through the same models. Finally, with the design results, its electromagnetic properties are analyzed by two finite element simulation software, and results meet requirements of the prototype.