Abstract:
The flashover voltage test results under laboratory atmospheric condition of external insulation are usually converted to the standard atmospheric condition by international or national standard. Thus, this thesis presents the study of the conversion of flashover voltage of Pin-post and Line-post insulator under atmospheric conditions in high voltage laboratory to standard atmospheric conditions recommended by international standard: IEC 60060-1:1989/IEEE4:1995, IEEE4 Amendment1 Std4a:2001 and national standard: ANSI C29:1 1988. For the high humidity of Thailand, the studies show that the humidity correction factor recommended by ANSI C29:1 1988 is suitable, while those recommended by IEC 600060-1: 1989 is appropriate only for negative impulse voltage. For positive impulse and AC voltage test according to IEC 60060-1: 1989, a new humidity correction factor is proposed.
