Funding for this research was provided by:
National Natural Science Foundation of China (51822508)
Department of Science and Technology of Sichuan Province (2020JDTD0012)
State Key Laboratory of Traction Power (2020TPL-T06)
fundamental research funds for the central universities (2682021CX028)
Article History
Received: 27 January 2021
Accepted: 16 August 2021
First Online: 23 August 2021