1. State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, Hebei University of Technology, Tianjin, China
2. Electric Power Research Institute, State Grid East Inner Mongolia Electric Power Co., Ltd., Hohhot, China
3. Shibei Power Supply Branch of State Grid Chongqing Electric Power Company, Chongqing, China
4. School of Electrical Engineering and Automation, State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, China