[1] Shanghai Maritime Univ, Elect Engn Dept, Shanghai 201306, Peoples R China
[2] Zhejiang Hengfu Elect Co Ltd, Photovolta Div, Hangzhou 310000, Peoples R China
[3] Tech Univ Crete, Sch Elect & Comp Engn, Khania 73100, Greece
[4] City Univ Hong Kong, Dept Elect Engn, Kowloon, Hong Kong 999077, Peoples R China
[5] City Univ Hong Kong, Ctr Smart Energy Convers & Utilizat Res, Kowloon, Hong Kong 999077, Peoples R China
[6] Christian Albrechts Univ Kiel, D-24118 Kiel, Germany
[7] Aalborg Univ, Energy Engn Dept, DK-9100 Aalborg, Denmark