Micro-Gap Discharge Phenomena in Air and SF₆ Gas

抄録

For improvement of detection techniques on the partial discharges in gas-insulated substations, it
is important to make clear the physical process of micro-gap discharge in air and in SF₆ gas.
The discharge current wave shapes and temporal variations of the emitted light were observed using a streak camera, and a simulation of spark-type discharge process in micro-gap was also performed.
The measured results show that as the gap size increases from 0.5 to 3.5mm, front time T_f and tail time T_t of the discharge current wave shapes in air increase from 1 and 20 ns to 2 and 51 ns, while the current peak value I_p decreases from 2.6 to 0.2 A. On the other hand, in SF₆ gas, T_f and T_t are shorter and I_p is greater than those in air. The measured results on temporal variation of the discharge light show that there is some difference in the wave shapes between the current and the emitted light. The calculated results on the wave shapes of discharge current and emitted photons indicated clearly these characteristics.