UHV power transmission is of enormous economic benefits and technical advantages,and has found wide application abroad.As the present 500 kV grid can not meet the demands of long-distance and large-capacity power transmission in southern power grid of China,it is suggested that 1 000 kV UHV AC transmission should be developed.In view of the large transmission capacity and high technical requirements of the UHV AC transmission line as well as its great influence on the stability of the system,this paper pres...