LI Shuang, LI Bin, TANG Jianeng, et al. Calculation on Floating Discharge Caused by Arc Extinguish Chamber Bias of 550 kV Tank-type Circuit Breaker[J]. High voltageapparatus, 2019, 55(6): 45-50.
LI Shuang, LI Bin, TANG Jianeng, et al. Calculation on Floating Discharge Caused by Arc Extinguish Chamber Bias of 550 kV Tank-type Circuit Breaker[J]. High voltageapparatus, 2019, 55(6): 45-50. DOI: 10.13296/j.1001-1609.hva.2019.06.006.
Calculation on Floating Discharge Caused by Arc Extinguish Chamber Bias of 550 kV Tank-type Circuit Breaker
To reveal the floating discharge in a 550 kV tank-type circuit breaker and propose a countermeasure
the forces on the insulator shielding ring is analyzed according to the principles of engineering mechanics. A critical breakdown distance criterion is proposed by adopting the stream breakdown theory
and the effectiveness of the criterion is verified via ELECNET. The results show that arc extinguish chamber bias causes uneven force on the insulator shielding ring
and a gap between the shielding ring and the end closure sustaining flange will form under external force. Only when the distance of the gap is in the range from 0 to 1.19 mm
floating discharge will occur. The floating discharge can be avoided by using an equipotential wire to connect the insulator shielding ring and the end closure sustaining flange
and setting an insulating tape with thickness of 1 mm betweenthem.