Funding for this research was provided by:
National Natural Science Foundation of China (51675443, 51735012)
the Independent Research and Development Projects of State Key Laboratory of Traction Power, Southwest Jiaotong University, China (2017TPL_T02, 2018TPL_T05)
Article History
Received: 3 January 2019
Accepted: 26 April 2019
First Online: 7 May 2019