In this paper, we investigated the lighting impulse
voltage breakdown characteristics of vacuum interrupters
with contact gaps 10 to 50mm and how thre contact
parameters inflence the breakdown characteristics. As a
result, the following points were indentifid:
(l)The breakdown probability distribution followed a
Weibull distribution when the breakdown voltage
saturated with contact gaps 10 to 50mm.
(2) 50% breakown voltage Uso depends on the contact
gap d, can be expressed by a equation Uso=kdu. And we
foun the different dependency of contact gap between
d=1O�30mm (a "" 0.72) and d=30�50mm ( a"" 0.55).
(3)50% breakdown voltage of vacuum interrupter with
contact radius of curvature 2mm was signifiantly higher
than that of vacuum interrupter with contact radius of
curvature 6mm. And the 50% breakdown voltage of
contact roughness 1.61l was close to that of contact
roughness 3.2ll. The 50% breakdown voltage of the
contact diameter 60mm was close to that of contact
diameter 75mm.