Luminous Characteristics during Discharge over the Spacer Surface in Sulfur Hexafluoride Gas
Chen Qingguo¹, Zhang Qiaogen¹, Qiu Yuchang¹, Wei Xinlao²
(1. Xi'an Jiaotong University, Xi'an 710049,China; 2. Harbin Institute of Technology)

Abstract: Optical signals occurred during the pre-discharge and the breakdown over the spacer in sulfur hexafluoride gas are investigated by using a photomultiplier tube and a high speed framing camera under the fast oscillating impulse voltages (FOI) or lightning impulse voltages (LI).The resultsshow that the ionization and combination can occur more easily under FOI than that under LI, which might result in the low discharge voltage. From the results, it can also be derived that the discharge mechanism under FOI is different from that under LI. The breakdown characteristics under LI can be bexplained by theprecursor mechanism, whereas under FOI it can be explained by the combination mechanism of precursor and high frequency.
Keywords: predischarge;photomultiplier;high speed framing camera;sulfur hexafluoride£»fast oscillating impulse voltages