PROJECT TITLE :

Influence of barrier on corona discharge activity in liquid nitrogen under AC voltages adopting UHF technique

ABSTRACT:

In liquid nitrogen insulation, the corona inception voltage is high with barrier within the electrode gap. The breakdown voltage of needle-plane gap has increased with barrier positioned close to high voltage needle electrode. The present signal injected thanks to corona discharge in liquid nitrogen insulation, at the purpose of its inception and during streamer formation, have rise time, in negative and positive cycle of the AC voltage are regarding 2.nine ns and 2.5ns respectively and also the characteristics has not altered because of barrier insulation. The UHF signal generated by corona discharges, in the liquid nitrogen electrode gap (with/without barrier) have frequency contents between 0.5-one.five GHz. The magnitude of UHF signal shaped thanks to corona activity (with barrier) on inception and at higher voltages (not at purpose of near breakdown) shows inverse relationship. Corona discharge followed with breakdown studies analyzed using zero span analysis. Phase resolved partial discharge signatures obtained thanks to corona discharges indicates that part window at that corona discharge occurs become slender with barrier in the electrode gap.