Dielectric recovery property measurements of CO2 and air arcs under free recovery condition using power semiconductors

This paper reports dielectric recovery property measurements of CO
2
and Air arcs under free recovery condition. In these measurements, the arc current and the voltage applied to the free recovery arcs were controlled with a high accuracy in time using power semiconductors. The recovery properties were measured by changing the application delay time t
d
of the recovery voltage with a peak of 8.2 kV. As a result, 200 L/min of CO
2
gas flow needs t
d
= 165 μs to withstand the quasi-TRV application with 50% probability of arc re-ignition; while 200 L/min of Air gas flow requires t
d
= 220 μ for the same purpose.