Electric Power Research Institute State Grid Shanghai Municipal Electric Power Company Shanghai 200437 P.R. China;
East China Electric Power Test and Research Institute Co. Ltd Shanghai 200437 P.R. China;
Department of Electrical Engineering Shanghai Jiao Tong University Shanghai 200240 P.R. China;
Electric Power Research Institute State Grid Shanghai Municipal Electric Power Company Shanghai 200437 P.R. China;
Department of Electrical Engineering Shanghai Jiao Tong University Shanghai 200240 P.R. China;
Electric Power Research Institute State Grid Shanghai Municipal Electric Power Company Shanghai 200437 P.R. China;
Department of Electrical Engineering Shanghai Jiao Tong University Shanghai 200240 P.R. China;