1. Department of High Voltage Engineering, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan 430070, P. R. China
2. State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan 430070, P. R. China
3. Key Laboratory of Pulsed Power Technology, (Huazhong University of Science and Technology), Ministry of Education, Luoyu Road 1037, Wuhan 430070, P. R. China
4. State Grid Jiangxi Electric Power Co Ltd Electric Power Research Institute, Minqiang Road 88, Nanchang 330000, P. R. China