| Title |
Characterisitcs of Lightning Impulse Corona Discharges in SF?/CO₂ Mixtures |
| Authors |
Bok-Hee Lee ; Young-Hwan Baek ; Sung-Kyun Oh ; Chang-Hwan Ahn |
| Keywords |
Prebreakdown phenomenon ; Nonuniform electric field ; Corona current ; Light emission images ; Discharge channel path |
| Abstract |
This paper presents experimental results relating to the preliminary breakdown characteristics in SF?/CO₂ gas mixtures under a highly non-uniform electric field. The impulse pre-breakdown developments are investigated by the measurements of corona current and light emission images. As a result, the preliminary breakdown development mechanisms for both the positive and negative polarities were fundamentally same. The first streamer corona was initiated at the tip of needle electrode, and the leaders developed with a stepwise propagation and bridged the test gap. The pause time of leader pulses in the positive polarity was significantly shorter than that in the negative polarity. Also, the time interval between the first streamer corona onset and breakdown in the negative polarity was much longer than that in the positive polarity. The discharge channel path in the positive polarity was zigzag, and the leader channel in the negative polarity was thicker and brighter than that in the positive polarity. |