GIS母线快速接地开关悬浮放电诊断和分析

针对某220 kV变电站快速接地开关气室异常放电现象，采用多种带电检测技术进行了诊断。通过特高频局部放电检测、超声波局部放电检测、声学成像等技术手段，判定该快速接地开关气室异常放电型式为悬浮放电。考虑到在SF₆气体取样测试中，测出绝缘气体中含有SO₂、H₂S等放电并伴有过热迹象的分解残留组分，对该故障气室进行停电解体，进一步分析讨论了放电异常成因。结果表明：引起接地开关悬浮放电的主因是气室内传动轴四方接头与传动绝缘子轴孔之间间隙过大，且连接部位金属嵌件凹槽间未安装等电位弹簧，使得两者间无法形成稳固的等电位。

Diagnosis and analysis of suspension discharge of GIS bus fast earthing switch

A variety of online detection techniques are used to diagnose abnormal discharges in the gas chamber of a quick earthing switch in a 220 kV substation.Through technical means such as ultra-high frequency partial discharge detection,ultrasonic partial discharge detection,and acoustic imaging,the type of abnormal discharge in the quick earthing switch''s gas chamber is determined to be suspension discharge.It is decided to deenergize and disassemble the faulty gas chamber in light of the detection of decomposition byproducts such as SO₂ and H₂S,as well as signs of overheating in the SF₆ gas during sampling tests.Subsequently,an in-depth analysis and discussion of the causes of the abnormal discharge are conducted.The results indicate that the primary cause of the suspension discharge in the earthing switch is an excessive gap between the square joint of the transmission shaft and the transmission insulator''s shaft hole within the gas chamber.Additionally,the absence of the equipotential bonding springs between the metal insert grooves at the connecting points prevents the formation of a stable equipotential field between them.