基于特征气体SO2F2的SF6气体绝缘设备的过热性故障诊断

利用SF₆分解产物检测来判断GIS故障发展程度已成为一种有效手段,在搭建的实验平台上展开200℃~360℃局部过热模拟实验,研究SF₆热分解特性。当实验温度较高时(320℃~360℃),新增SO₂F₂、H₂S、COS三种产物。在绝缘设备充满大量SF₆子的背景下,分解产生的H₂和COS的含量极少,给气体检测带来了困难。文中提出将SO₂F₂作为设备故障进入严重状态的标志气体,同时用量子化学计算法在B3LYP/6-311G(+d,p)水平下对SO₂F₂生成机理和能量条件进行研究。发现SO₂F₂通过F₂碎片与气室内SO₂反应、F原子与SO₂F结合、SOF 4水解反应这三条途径得到,其中SO₂与F₂反应是SO₂F₂的主要来源。实验现象与理论计算均表明:SO₂F₂的形成机制与高温息息相关,SO₂F₂出现,标志着设备故障处温度较高,SF₆绝缘能力已遭到严重破坏。

Overheating Fault Diagnosis of SF6 Insulation Equipment Based on Characteristic Gas SO2 F2

It has become an effective method to judge the fault development of GIS by using the detection of SF₆decomposition products.Overheating simulation experiments were carried out on the established experimental platform to study the thermal decomposition characteristics of SF6.When the experimental temperature was high(320℃~360℃),SO₂F₂、H₂S and COS were detected.Under the background that the gas insulation equipment is filled with a large amount of SF₆,the amounts of H₂S and COS is very small,which poses a great challenge to gas detection.Based on this,the generationof SO₂F₂can effectively reflect the SF₆insulated equipment is under deteriorating.Meanwhile,the generation mechanism and energy conditions of SO₂F₂are studied at B3LYP/6-311g(+d,p)level by using quantum chemical calculation method.It was found that SO₂F₂was produced mainly through the following three reaction pathways:F₂+SO₂→SO₂F₂,F+SO₂F→SO₂F₂,SOF 4+H₂O→SO₂F₂+2HF.Experimental phenomena and theoretical calculations have shown that the formation mechanism of SO₂F₂is closely related to fault temperature.The presence of SO₂F₂indicates that the fault temperature of the equipment is high and SF₆insulation capability has been seriously damaged.