Critical flashover voltage of short HV insulator covered with ice at low atmospheric pressure

The main purpose of the present paper is to investigate the effects of high altitude on AC flashover of a short insulator covered with ice. The experiments were carried out in an evacuated chamber in which the air pressure condition at high altitude up to 9000 m may be simulated. It was found that low pressure at high altitudes could reduce the minimum flashover voltage of the short insulator covered with ice. The results also showed that the effects of low air pressure on the minimum flashover voltage of ice-covered insulators depend on insulator profile.