1. College of Electrical Engineering and Automation, Shandong University of Science and Technology, Tsingtao, China
2. State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi'an Jiaotong University, Xi'an, China
3. Pinggao Group Co., Ltd., Pingdingshan, China
4. State Grid Zhejiang Electric Power Company, Hangzhou, China
5. XJ Electric Co., Ltd., Xuchang, China