Partial Discharge Suppression of the Oil-impregnated Paper by Depositing PTFE Thin Film via Magnetron Sputtering

Abstract

Abstract The rapid development of HVDC (High Voltage Direct Current) transmission technology brings new challenges to insulation materials. Oil-paper insulation needs to be strengthened to prevent possible breakdown failure. In this paper, the PTFE functional film was fabricated by magnetron sputtering on the insulation pressboard surface to suppress partial discharge. The partial discharge test was conducted to compare the withstanding ability of the modified pressboard and the untreated pressboard. The results showed that partial discharge inception voltage increased by 18% for the modified pressboard. Phase-resolved partial discharge results also showed a great enhancement in partial discharge withstanding the ability of the PTFE function layer on the pressboard. The molecular simulation was conducted to give a possible explanation for the improvement. Higher bond levels and a large band gap of PTFE played a vital role.