Significantly suppressing metal particle-induced surface charge accumulation of spacers in DC gas-insulated power transmission lines

Abstract In this letter, we report functions of surface roughening and fluorination on suppressing linear metal particle-induced spacer surface charge accumulation. An appropriate increase in spacer surface conductivity by short-term fluorination and roughening not only increases the metal particle lifting voltage, but also weakens the particle activation. The spacer surface charge shows reduced charge density in roughened spacer, while fluorination modification significantly suppresses the charge density on the spacer surface. For roughened and fluorinated samples, the decrease of surface charge density and the intrinsic lower electric field (due to an increase in conductivity) near the triple junction both contribute to a higher particle lifting voltage. The content in this letter provides an approach to effectively suppress the charge accumulation induced by linear metal particles.