Supporting insulator, insulating supporting structure and direct-current GIL

The invention belongs to the field of direct-current power transmission, and particularly relates to a supporting insulator, an insulating supporting structure and a direct-current GIL. In order to solve the technical problem that in the prior art, an electric field line penetrates out of a supporting insulator, and consequently the normal field intensity of the side face of the supporting insulator is too large, the invention provides the supporting insulator which comprises a high-potential supporting face used for supporting a conducting rod, a low-potential supporting face used for supporting an insulating cylinder and a side face. The high-potential supporting surface and the low-potential supporting surface are arc-shaped surfaces, the axes of the high-potential supporting surface and the low-potential supporting surface correspond to the axis of the matched conducting rod, and the extension line of the projection of the side surface of the supporting insulator in the axis direction of the corresponding