[1] Xi An Jiao Tong Univ, Dept Elect Engn, State Key Lab Elect Insulat & Power Equipment, Xian 710049, Peoples R China
[2] Xi An Jiao Tong Univ, Dept Comp Sci, Xian 710049, Peoples R China
[3] Tsinghua Univ, State Key Lab Power Syst, Beijing 100084, Peoples R China