SF_6气体中绝缘子沿面放电的发光特性

Luminous Characteristics during Discharge over the Spacer Surface in Sulfur Hexafluoride Gas

利用光电倍增管及高速摄影机 ,对SF6气体中绝缘子沿面预放电及放电通道形成过程中的发光进行了检测 ,得出快速振荡冲击 (FOI)比雷电冲击 (LI)更容易使绝缘子沿面的SF6气体产生电离与复合 ,从而造成快速振荡冲击电压下 ,极不均匀场中绝缘子沿面放电电压的降低 .试验结果还证实 ,雷电冲击下绝缘子沿面放电遵循先驱机理 ,而快速振荡冲击下放电遵循先驱与高频联合机理 .

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 results show 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 the precursor mechanism, whereas under FOI it can be explained by the combination mechanism of precursor and high frequency.