[1] Tianjin Univ, Key Lab Smart Grid, Minist Educ, Tianjin 300072, Peoples R China
[2] Hebei Univ Technol, State Key Lab Reliabil & Intelligence Elect Equipm, Tianjin 300130, Peoples R China
[3] Aalborg Univ, Dept Energy Technol, DK-9220 Aalborg, Denmark
[4] Tech Univ Catalonia, Dept Elect Engn, Barcelona 08019, Spain