1. Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China
2. Hubei Key Laboratory of Advanced Technology for Automotive Components, Wuhan University of Technology, Wuhan 430070, China
3. University of Chinse Academy of Sciences, Beijing 100049, China
4. Institute of Electrical Engineering and Advanced Electromagnetic Drive Technology, Qilu Zhongke, Jinan 250013, China