1. School of Locomotive and Rolling Stock Engineering, Dalian Jiaotong University, Dalian 116028, China
2. New Product Development Department, CRRC DALIAN Co., Ltd., Dalian 116021, China
3. School of Electronic Information and Automation, Civil Aviation University of China, Tianjin 300300, China
4. Traction Power State Key Laboratory, Southwest Jiaotong University, Chengdu 610031, China