机—电联合作用下尖端电极中金属微粒的运动行为与局部放电特性

Motion Behavior and Partial Discharge Characteristics of Metal Particles in Tip Electrode Under Mechanical and Electrical Combined Action

GIS内自由金属微粒的运动、集聚行为导致金属微粒在电力设备内部分布广泛,使得绝缘子表面的闪络电压降低,对设备的绝缘状态造成潜在性的威胁。本文搭建自由金属微粒机—电联合试验平台,研究机—电共同作用下尖端电极中金属微粒的放电特性与运动特性,总结出工频电压和机械振动对于金属微粒起跳及运动行为的影响规律。试验结果表明尖端电极下,球形微粒与线性微粒均保持在底电极上沿弧面进行小幅滚动,增加工频电压幅值会使得微粒沿弧面晃动的上下界高度提升,增加机械振动幅值会使得微粒出现一定的起跳动作,且运动的随机性增加;放电产生的PRPD谱图整体保持尖端放电的典型特征,飞行谱图整体保持三角脉冲群的典型特征,但仅存在单一的三角峰,并从受力分析与空间电荷的角度对运动行为与放电特性进行解释。文中的研究为实际工程应用多缺陷中金属微粒的检测提供了一种有效的方法。

The motion and agglomeration behavior of free metal particles in GIS lead to wide distribution of metal particles in power equipment,which reduces the flashover voltage of insulator surface and poses a potential threat to the insulation condition of the equipment.In this paper,a mechanical-electrical joint test platform of free metal parti-cle is built to study the discharge and motion characteristics of metal particles in the tip electrode under the mechan-ical and electrical combined action,and the influence of power frequency voltage and mechanical vibration on the jump and motion behavior of metal particles is summarized.The test results show that under the tip electrode,both spherical and linear particles are kept on the bottom electrode to roll slightly along the arc surface.Increasing the am-plitude of power frequency voltage will increase the height of the upper and lower bounds of the particles sloshing along the arc surface.Increasing the amplitude of mechanical vibration will make the particles jump to a certain ex-tent,and the randomness of the movement increases.The PRPD spectrum generated by the discharge maintains the typical characteristics of the tip discharge as a whole,and the flight spectrum maintains the typical characteristics of the triangular pulse group as a whole,but there is only a single triangular peak.The motion behavior and discharge characteristics are explained from the perspective of stress analysis and space charge.The research in this paper pro-vides an effective method for the detection of metal particles in multiple defects in practical engineering applications.