ZHAN Huamao, LIU Bo, SHI Wei, et al. Influence of Space Charge on Air Gap Discharge Under Switching Impulse[J]. High voltageapparatus, 2014, 50(2): 92-98.
ZHAN Huamao, LIU Bo, SHI Wei, et al. Influence of Space Charge on Air Gap Discharge Under Switching Impulse[J]. High voltageapparatus, 2014, 50(2): 92-98. DOI: 10.13296/j.1001-1609.hva.2014.02.017.
Influence of Space Charge on Air Gap Discharge Under Switching Impulse
Shielding failure is the main factor for lightning trip-out of EHV and UHV transmission lines
and space charge plays an important role in the shielding failure accident.In order to investigate the influence of space charge on lightning discharge
a rod-line air gap of 150 cm in length was set up.Under the positive and negative switching impulse voltage
the discharge process of the gap was observed by a high speed video camera system and statistical analysis on the number of strikes on the line electrode with different diameter was performed.The current flowing through the positive rod-line air gap was measured to obtain the charge current
and the integral of the charge current was calculated to evaluate the amount of space charge.The influence of space charge on the electric field in the vicinity of the line electrode was explored through the ANSYS.Experimental results showed that shielding effect of space charge on discharge strike point is significant under positive switching impulse voltage
but under negative switching impulse voltage
this shielding effect is not a leading factor influencing strike number and discharge path.The shielding effect of space charge is related with the size of line electrode.The larger the line electrode diameter is
the smaller the shielding effect of space charge becomes.