Influence of humidity on the breakdown voltage of a sphere-sphere gap, at the 2 600 M O.S.L.

LILIANA BEJARANO; FRANCISCO ROMÁN; A.A. ROMERO

Delft

Congreso; 13th International Symposium on High Voltage Engineering; 2003

13th International Symposium on High Voltage Engineering

An investigation report of the possible effects of humidity on the 50% probability breakdown voltage of a sphere-sphere gap configuration in air at the altitude of 2 600 meters over sea level is presented in this paper. Positive lightning impulse voltages were applied. The tests were carried out at the High Voltage Test Laboratory of the Universidad Nacional de Colombia in Bogotá, Colombia. Environmental conditions of humidity and temperature were controlled. The multiple level test method MLM was used. Additionally, 20 breakdown impulses of the last MLM level were recorded and analyzed. No significant differences in 50% probability breakdown voltage for different values of humidity and temperature at the test conditions were found. In the 20 recorded breakdown impulses no evidence on predisruptive events were observed. Nevertheless, the results show that the correction factors for the relative density of air proposed in IEC Standard 52 and IEC Standard 60-1 are not adequate for Bogotá test conditions. For this reason, correction factors for the relative air density of the experimental conditions are suggested.