1. College of Aerospace Engineering, Chongqing University, Chongqing, China
2. State Grid Henan Electric Power Research Institute, Zhengzhou, China
3. Inner Mongolia Enterprise Key Laboratory of High Voltage and Insulation Technology, Hohhot, China
4. School of Civil Engineering, Chongqing Jiaotong University, Chongqing, China
5. Nanjing Electric Power Fittings Design and Research Institute Company Ltd., Nanjing, China