Ms
1.Applied Superconductivity Laboratory, State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu, Sichuan 610031, China.2School of Electrical Engineering, Southwest Jiaotong University, Chengdu 610031, China. 2.School of Electrical Engineering, Southwest Jiaotong University, Chengdu 610031, China.2School of Electrical Engineering, Southwest Jiaotong University, Chengdu 610031, China.