1. School of Information Science and Technology, Southwest Jiaotong University, Chengdu, China
2. State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu, China
3. School of Electrical Engineering, Southwest Jiaotong University, Chengdu, China
4. Research Center for Super-High-Speed Evacuated Tube Maglev Transport, Southwest Jiaotong University, Chengdu, China