Charge accumulation at the gas-solid interface of DC gas insulated switchgear/gas insulated transmission lines(GIS/GIL) insulation systems is a primary cause of localized electric field distortion and induced surface flashover

posing a serious threat to long-term operational reliability. Extensive research has been conducted worldwide on charge regulation methods at the gas-solid interface of insulators. Among these

surface modification techniques hold broad application prospects for DC GIS/GIL insulators due to their advantages of preserving the volumetric properties of solid insulating materials

simplicity of operation

and low costs

making them a current research hotspot. This paper reviews surface modification methods for controlling gas-solid interface charge in DC GIS/GIL insulation systems. This paper first summarizes research achievements in methods such as surface grinding

direct fluorination

and plasma treatment of insulating materials by domestic and international scholars. Second

this paper focuses on the currently widely studied surface coating methods

and summarizes significant research progress in functional surface coating techniques for gas-solid interface charge control. Finally

this paper outlines core scientific and technological challenges that remain to be addressed in surface modification methods for gas-solid interface charge regulation.