1. School of Mechanical Engineering, Southwest Jiaotong University, Chengdu 610031, China
2. Engineering Research Center of Advanced Drive Energy Saving Technologies, Ministry of Education, Southwest Jiaotong University, Chengdu 610031, China
3. Technology and Equipment of Rail Transit Operation and Maintenance Key Laboratory of Sichuan Province, Southwest Jiaotong University, Chengdu 610031, China