252 kV GIS灭弧室绝缘故障的电热耦合仿真分析

Simulation Analysis of Electric Heating Coupling of Insulation Fault in 252 kV GIS Arc Extinguishing Chamber

针对某型号252kV气体绝缘金属封闭开关设备(gas insulated metal-enclosured switchgear,GIS)灭弧室故障和设备解体过程发现的问题,判断触头接触不良,仅弧触头形成接触、主触头未形成接触是造成故障的直接原因。利用ANSYS软件建立了故障灭弧室1 ∶ 1三维有限元模型,考虑了接触电阻随温度变化的特性,进行电热耦合场及静电场仿真,获得灭弧室内的三维温度场及电场分布,如内部载流系统的温升、断口间和屏蔽罩的电场分布等,从而揭示故障中放电路径的形成原因,还原故障过程,为该型号GIS灭弧室的安全运行提供了理论支撑。

Problems found in the fault of one typed 252 kV GIS arc extinguishing chamber and its disassembly process are analyzed. The bad contact of contacts been discovered is the direct reason for causing the fault. A 1 ∶ 1 3D finite element model of the faulted arc extinguishing chamber is built in ANSYS. The temperature dependence of the contact resistance is considered. Simulations on electric-thermal coupling field and electrostatic field are made. The 3D temperature field and electric field distribution in the arc extinguishing chamber are obtained, such as temperature rise of the current carrying system, electric field distribution of contacts and shielding cases. Thus, the forming of discharge paths is revealed and the fault process is restored, which can provide theoretical supporting for safe operation of this typed GIS arc extinguishing chamber.