1. State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
2. School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
3. Institute of Electric Power Science of Guizhou Power Grid Co., Ltd., Guiyang, Guizhou 550000, China