[1] North China Elect Power Univ, State Key Lab Alternate Elect Power Syst Renewabl, Beijing 102206, Peoples R China
[2] North China Elect Power Univ, Sch Control & Comp Engn, Beijing 102206, Peoples R China
[3] State Grid Liaoning Elect Power Supply Co Ltd, Shenyang 110006, Peoples R China
[4] Univ Leeds, Sch Elect & Elect Engn, Leeds LS2 9JT, W Yorkshire, England