摘要
以一起气体绝缘金属封闭开关设备(gas insulator switchgear,GIS)接地开关短路事故为例,分析事故发生的原因是隔离开关气室内金属异物在电场力和机械振动的作用下,引起盆式绝缘子沿面放电,导致绝缘破坏;在重合闸过程中,盆式绝缘子再次发生放电,电弧在气流的作用下,引起隔离开关静触头屏蔽罩与筒壁发生短路,强大的电流导致屏蔽罩烧熔。由此判断厂内装配环境控制不严格以及金属异物等杂质严重威胁着GIS的安全。提出相关建议,即加强对GIS生产过程的控制,保证GIS内部清洁;同时,要加强对运行中的GIS的局部放电检测,对存在局放信号的GIS设备及时进行检查,以确保电网安全稳定运行。
The paper takes a short circuit accident of earthing switch of gas insulated metal-enclosed switchgear as an example to analyze that it is caused by discharge on the verge of cone type insulator resulting from metal objects in the chamber under the action of electric field force and mechanical vibration, which breaks the insulation. During the reclosing, the cone type discharges once more, which causes short circuit between shielded enclosure of fixed contact and tunnel wall under the action of airflow-affected electric arc, and shielded enclosure is consequently burnt out by heavy current. It is judged that inexact installation environment and impurity such as metal objects severely threaten safety of GIS. It also puts forward suggestions like strengthening control of GIS production and keeping the interior of GIS clean. In the meantime, importance of PD test should be attached to and GIS with PD signals should be examined in time to ensure safe and stable operation of grid.
出处
《广东电力》
2011年第11期106-108,共3页
Guangdong Electric Power
基金
973项目资助(2009CB724508)
