[1] Jiangsu Univ, Jiangsu Prov & Educ Minist Cosponsored Synergist I, Sch Elect & Informat Engn, Zhenjiang 212013, Peoples R China
[2] Jiangsu Univ, Sch Elect & Informat Engn, Zhenjiang 212013, Peoples R China
[3] State Grid Xuzhou Power Supply Co, Xuzhou 221005, Peoples R China
[4] Zhejiang Univ, Coll Elect Engn, Hangzhou 310027, Peoples R China