DENG Heming was born in Hubei, China in 1979. He received the B. Eng. degree from Chengdu University of Technology in 2003, the M. Sc. degree in geochemistry from Institute of Geochemislry, Chinese Academy of Science in 2006, and the Ph.D. degree in Huazhong University of Science and Technology in 2010. His main research interests include high voltage and insula- tion technology, discharges of two-phase mixtures and plasma miques in environmental engineering, high voltage and insulation, etc all: denghem@gmail.com (027)59833625 ZHANG Guangzhou was born in Shandong, China in 1975. He received the B, Eng. degree from Wuhan University in 1997, the M. Eng. degree from Huazhong University of Science and Technology in 2006, and the Ph.D. degree in electrical engineering from Wuhan University in 2012. Now he is a senior engineer in State Grid Electric Power Research Institute. His main research interests include high voltage and insula- tion technology, electromagnetic compatibility and electromagnetic environment in power system. XU Yuhang was born Fujian, China in 1986. He received the B. Eng. degree from South China University of Technology in 2008, and M. Eng. degree in Huazhong University of Science and Technology in 2010. His main research interests include high voltage and insulation, pulsed power techniques.