Research on the Operating Process of DC De-icer and Its De-icing Efficiency in China Southern Power Grid

The China Southern Power Grid (CSG) has installed 6 sets of DC-deicer on its backbone transmission grid since the ice disaster in 2008, among which the DC-deicer in Gaopo substation of Gao-Zhao ±500kV DC transmission lines is the first OPGW deicer in CSG. Most of the existing DC-deicing research work concerns on the analyzing of transmission lines without considering the installation of de-icing switches. However, the icing problem of overhead ground lines has become the secondary influencing factor in the causation of power system fault during winter. Given this background, the general situation of the 6 sets of DC de-icer is presented and the de-icing operating process and its efficiency after the installation of de-icing switches are studied. Finally, suggestions are given on basis of the research.