Evaluation Methods of Contamination Flashover Voltage Performance of Cylindrical Type Semi-conducting Glaze Porcelain Insulators

摘要

Higher contamination flashover voltage of a semi-conducting glaze(SG) insulator owes mainly to the drying effect by leakage current flowing in the glaze. Significant reduction in contamination flashover voltage was confirmed on a cylindrical SG insulator when fog density was increased from 4～5 g/m~3 to 13 g/m~3 in clean fog test. The effect of de-energized time duration between trip-out and re-energization on the contamination flashover voltage of a cylindrical SG insulator under cold-wet switch-on conditions was investigated. The shorter the de-energized time duration, the higher the flashover voltage. Higher contamination design voltages may be adopted even under cold-wet switch-on conditions.