Processes in insulating gas induced by electrical breakdown responsible for commercial gas-filled surge arresters delay response

- Processes induced by electrical breakdown in insulating gas were investigated.
- CITEL, SIEMENS and EPCOS gas filled surge arrester were used in experiments.
- Processes were analyzed on the basis of memory curves obtained in experiment.

Examination of electrical breakdown time delay td as a function of relaxation time τ and analyzing of processes in insulating gas responsible for delay response of commercial gas-filled surge arresters (GFSA) manufactured by CITEL, SIEMENS and EPCOS was performed. It was shown that positive ions remained from previous breakdown and discharge, as well as positive ions formed in post discharge have a dominant role in breakdown initiation up to τ≈1.5s. In this case delay response is determined only by formative time in insulating gas. In insulating gas of GFSA manufactured by CITEL in the 1.5s<τ<3.103s interval the dominant role in breakdown initiation is due to long living electrically neutral active particles and delay response is determined by statistical time delay. The irradiation of these devices with low doses of gamma rays leads to decrease in delay response down to the values which correspond to formative time in insulating gas. Presented results show that full relaxation of processes in insulating gas after breakdown and discharge ceases for GFSAs manufactured by SIEMENS and EPCOS occur for τ≈200ms, while for GFSAs manufactured by CITEL such relaxation occurs for about 3.103s.