[1] Kunming Univ Sci & Technol, Fac Met & Energy Engn, Kunming 650093, Peoples R China
[2] Kunming Univ Sci & Technol, Fac Elect Power Engn, Kunming 650500, Peoples R China
[3] Yunnan Power Grid Co Ltd, Dept Syst Operat, Kunming 650011, Peoples R China
[4] Measurement Ctr Yunnan Power Grid Co Ltd, Kunming 650041, Peoples R China