GIL内金属微粒在直流电压下的运动特性分析

气体绝缘金属封闭输电线路(gas-insulated metal-enclosed transmission line,GIL)以其输送容量大、占地面积小、传输损耗小等优点,在许多场合是替代电缆和架空线路的首选方案。但GIL内部的金属微粒会在电场的影响下发生起跳和运动,严重威胁了GIL的绝缘性能。为更好地捕获金属微粒,掌握GIL内金属微粒的受力和运动特性是十分有必要的。本文首先忽略了盆式绝缘子对GIL轴向场强的影响,分析了金属微粒在同轴圆柱间的受力和运动特性,使用金属微粒谐振频率表征金属微粒在直流电压下的活跃度,并分析了电压和微粒半径对金属微粒谐振频率的影响规律。然后考虑了盆式绝缘子对GIL轴向场强的影响,得到了金属微粒的几种典型的运动轨迹。最后给出了对于金属微粒陷阱布置的建议，认为在盆式绝缘子凸面侧下方布置金属微粒陷阱是必要的。

Motion characteristic of metal particles in GIL under DC voltage

Gas-metal-enclosed transmission line (GIL) is alternative to cable and overhead line because of its large transmission capacity, small floor space and low transmission loss. Metal particles of GIL will take off under electric field, which threatens the insulation performance of GIL. To better collecting metal particles, it is necessary to investigate the force analysis and motion characteristic of metal particles of GIL. Firstly, this paper analyzes the force and motion characteristic of metal particles between coaxial cylinder electrodes, under the condition that the influence of the basin-type insulators on the axial electric field strength is ignored. The resonant frequency of metal particles is used to characterize the activity of metal particles under DC voltage, and the influences of voltage and particle radius on the resonant frequency of metal particles are analyzed. Then, consider the influence of the basin-type insu-lator on the axial electric field intensity of GIL, several typical motion trajectories of metal particles are obtained. Finally, some suggestions for the layout of particle traps are given. The results show that it is necessary to arrange metal particle traps under the convex side of basin-type insulator.