1. The Xuefeng Mountain Energy Equipment Safety National Observation and Research Station of Chongqing University, Chongqing 400044, China
2. Department of Electrical and Electronic Engineering, The University of Manchester, Manchester M13 9PL, UK
3. Electric Power Research Institute of Guangdong Power Grid Co., Ltd., Guangzhou 510080, China
4. Oriental Cables, Ningbo 315100, China