The new research on air density correction factor [power line external insulation]

The authors summarize the results of joint research into the influence of altitude and atmospheric conditions on the disruptive discharge of external insulation of power transmission apparatus. The same tests on the same configuration and with the same procedures were performed at different altitudes (23 m, 506 m, 1040 m, 1890 m, 2300 m, and 3650 m above sea level). It is shown that the flashover voltages of external insulation of electrical facilities decrease with increase of altitude and decrease of air density. The correction factors of relative air density obtained from test results are nearly equal to the present correction factors in the IEC 60-1 standards and GB311-83 Chinese standards