[Fei, Zhineng; Li, Zhengmao] Aalto Univ, Sch Elect Engn, Espoo 02150, Finland.
[Yang, Hongming; Meng, Ke] Changsha Univ Sci & Technol, Coll Elect & Informat Engn, Changsha 410114, Peoples R China.
[Du, Liang] Temple Univ, Dept Elect Engn, Philadelphia, PA 19121 USA.
[Guerrero, Josep M.] Tech Univ Catalonia, Ctr Res Microgrids, Dept Elect Engn, Barcelona 08019, Spain.
[Guerrero, Josep M.] ICREA, Pg Lluis Co 23, Barcelona 08010, Spain.