[1] Nanchang Univ, Sch Informat Engn, Nanchang 330031, Peoples R China
[2] Univ Leicester, Sch Engn, Leicester LE1 7RH, Leicestershire, England
[3] Tech Univ Denmark, Dept Elect Engn, DK-2800 Lyngby, Denmark
[4] Univ Nottingham, Power Elect Machines & Control Grp PEMC, Nottingham NG7 2RD, England