Novel Spacer with Surface Functional Graded Materials for HVDC GIL

Under heavy load operating conditions, the fail rate of GIL spacers will be greatly increased. Flashover fault is the most frequently occurring failures in GIL, which seriously affects the safe operation of HVDC transmission systems. This paper introduced the problem of local electric field distortion of GIL spacers under working conditions, proposes a method to uniform surface electric field by constructing a functional gradient layer on the surface of spacers. Then this paper introduced the fabrication method of FGM insulation materials, including centrifugal method, 3D printing and flexible mixed casting. Some examples are given to introduce the current research status of the construction method of the surface functional layer of the novel spacers, including multilayer impregnation, magnetron sputtering and surface fluorination. Finally, the problems that need to be solved urgently and the direction of future research and development are pointed out.