1. School of Mechanical Engineering, Southwest Jiaotong University, Chengdu, People’s Republic of China
2. The State Key Laboratory of Heavy Duty AC Drive Electric Locomotive Systems Integration, Zhuzhou, People’s Republic of China
3. State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu, People’s Republic of China
4. Institute of Railway Research, University of Huddersfield, Huddersfield, UK
5. School of Automobile & Transportation, Xihua University, Chengdu, People’s Republic of China