[1] Yunnan Electric Power Research Institute (Group) Co., Ltd, Kunming 650051, China
[2] Guangdong Electric Power Research Insititute, Guangzhou 510080, China
[3] State Key Laboratory of Power Transmission Equipment and System Security and New Technology, Chongqing University, Chongqing 400030, China
[4] Chongqing Electric Power Research Insititute, Chongqing 401123, China