[Guo, Siyuan;Li, Li;Zhao, Yongsheng] State Grid Hunan Elect Power Co Ltd Res Inst, Changsha 410007, Peoples R China.^[Zhang, Shoushou] Cent South Univ Forestry & Technol, Bangor Coll, Changsha 410018, Peoples R China.^[Song, Junying] State Grid Hunan Elect Power Co Ltd, Changsha 410004, Peoples R China.