Free metal particle can affect surface charge accumulation on epoxy insulator installed in gas-insulated transmission line (GIL) or gas-insulated switchgear (GIS), which results in reduction of surface flashover voltage thus threatening the safe operation of the power equipment. This article reports on the charge accumulation behavior on a real size epoxy insulator with bouncing metal particle under DC voltage. A coaxial electrode system was designed for the test under -30 kV, a metal particle-launching system was employed to inject the bouncing linear particle to the insulator surface. The charge distribution was measured by a Kelvin-type probe, and the influence of the particle on the charge accumulation was analyzed with the help of electric field simulation. The results showed that there were mainly two moving patterns of the bouncing particle: the charges were accumulated with speckle shape and the charged particle that hit the edge of electrode had more remarkable influence on the charge accumulation than other particles. It is suggested that the charge distribution feature is dependent upon the collision point and the trajectory of the bouncing particle.

中文翻译：

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直流电压下具有弹跳金属颗粒的实际尺寸环氧绝缘体上的表面电荷积累


游离金属颗粒会影响气体绝缘输电线路（GIL）或气体绝缘开关设备（GIS）中安装的环氧绝缘子表面电荷积累，导致表面闪络电压降低，从而威胁电力设备的安全运行。本文报道了直流电压下具有弹跳金属颗粒的实际尺寸环氧树脂绝缘体上的电荷积累行为。设计了同轴电极系统用于-30 kV下的测试，采用金属粒子发射系统将弹跳的线性粒子注入绝缘子表面。通过开尔文型探针测量电荷分布，并借助电场模拟分析粒子对电荷积累的影响。结果表明，弹跳粒子的运动模式主要有两种：电荷以散斑状累积，撞击电极边缘的带电粒子对电荷累积的影响比其他粒子更显着。这表明电荷分布特征取决于碰撞点和弹跳粒子的轨迹。