[1] Chongqing Univ, Sch Elect Engn, Chongqing 400044, Peoples R China
[2] Chongqing Univ, Liyang Smart City Res Inst, Chongqing 400044, Peoples R China
[3] Chongqing Univ, Elect Engn, Chongqing, Peoples R China
[4] State Grid Chongqing Elect Power Co Res Inst, Chongqing, Peoples R China