Control of Metallic Particle Contaminants in Compressed Gas Insulated Sub-station (GIS) Equipment by Conductor Coating

压缩气体绝缘开关柜（GIS）通常采用SF6气体作为绝缘介质，目前已在世界范围内得到广泛应用，是城市高压开关电站建设的领先技术。它为电力供应公司提供了明显的优势。由于对空间要求低，GIS适用于各种类型的建筑。地理信息系统还保护环境，使其附近的人和动物免受电磁场的影响。它本身不受环境危害，如雷电和污染。地理信息系统的优点受到污染的导电颗粒的现象，这是不可避免地存在于外壳内。众所周知，金属颗粒会严重损害压缩气体绝缘变电站（GIS）设备的绝缘完整性。当这些颗粒靠近支撑绝缘子时，会产生特殊的危害。大多数地理信息系统设备制造商采用各种技术和设备，如静电粒子陷阱，以控制金属粒子污染。需要进一步的研究来检测这些颗粒的存在并减轻它们的影响，从而最大限度地减少计划外停机。电力供应的可靠性是重要的，其经济影响是公认的所有用户和供应商。在过去的几年里，人们对气体绝缘系统中高压电极上介质涂层的效率和效果进行了研究。数据表明，介质涂层有利于提高气体绝缘系统的击穿电压。此外，一些初步研究结果表明，这种涂层减少了金属颗粒对GIS设备的不利影响，从而提高了系统的可靠性。该项目的目的是使用建模和计算方法来研究导体涂层在减轻同轴GIS系统水平部分颗粒污染的不利影响方面的有效性。通过将粒子位置密度函数与给定GIS系统的击穿电压分布相结合，可以计算出金属颗粒存在时绝缘失效的概率。该数值模型还将用于研究粒子大小、间隙尺寸和电压波形等参数对粒子捕获的影响。理论结果将在实验中得到验证。首席研究员，研究了GIS设备中金属颗粒运动的动力学。他的研究包括使用一个综合的计算程序来分析各种参数对60赫兹电压下同轴电极系统中粒子运动的影响。美国堪萨斯州立大学、瑞典查尔姆斯理工大学和加拿大英属哥伦比亚大学将在该项目中完成国际合作。在堪萨斯州立大学，首席研究员将详细阐述单电极涂层的同轴电极系统中的粒子动力学模型，并预测一般情况下压缩气体绝缘输电线路（GITL）系统击穿电压分布和击穿概率的改进。需要进行实验工作来验证模型的结果。在Stanislaw Gubariski教授的指导下，实验数据将在查尔姆斯理工大学的高压实验室获得。拟议的合作将通过进行适当的实验来验证建模输出。拟议的研究将对美国城市能源基础设施的广泛领域产生影响，使压缩GIS/GITL技术更有效，更环保，更容易操作和维护。拟议中的项目应引起公用事业公司和制造商的兴趣。

Compressed gas-insulated switchgear (GIS), normally using SF6 gas as an insulating medium, is now widely established all over the world and represents the leading technique in the construction of high-voltage switching electric power stations in urban areas. It offers distinct advantages to power supply utilities. Due to low space requirements, GIS is adaptable to all types of buildings. GIS also provides environmental protection by shielding humans and animals in its vicinity from emanating electromagnetic fields. It is itself protected from environmental hazard, such as lightning and pollution. The advantages of GIS are compromised by the phenomenon of contaminating conducting particles which are inevitably present inside the enclosure. Metallic particles are known to drastically impair the insulation integrity of compressed gas insulated sub-station (GIS) equipment. Such particles present a special hazard when present in close proximity of support insulators. Most GIS equipment manufacturers employ a variety of techniques and devices, such as electrostatic particle traps, to control metallic particle contamination. Further research is vitally needed to detect the presence of these particles and mitigate their effects, and thus minimize unplanned outages. Reliability of electric supply is important and its economic impact is recognized by all users and suppliers. The efficiency and effectiveness of dielectric coatings on high voltage electrodes in gaseous insulation systems have been studied over the past several years. Data indicate that the dielectric coatings are beneficial and improve the breakdown voltage in gaseous insulation systems. Moreover, results of some preliminary studies show that such coatings reduce the adverse impact of metallic particles in GIS equipment, thus increasing the reliability of the system. The objective of this project is to use modeling and computational methods to investigate the effectiveness of conductor coating in mitigating adverse effec ts of particle contamination in a horizontal section of a coaxial GIS system. The probability of insulation failure in the presence of metallic particles can be calculated by combining the particle position density function with the breakdown voltage profile of a given GIS system. The numerical model also will be used to study the effect of parameters such as particle size, gap dimensions, and voltage waveshape on particle trapping. Theoretical results will be verified experimentally. The principal investigator, has studied the dynamics of metallic particle movement in GIS equipment. His research has included the use of a comprehensive computational program to analyze the effect of various parameters on the particle movement in coaxial electrode systems under 60 Hz voltage. International collaboration between Kansas State University, USA, Chalmers University of Technology, Sweden, and the University of British Columbia, Canada, will be accomplished in this project. At Kansas State University the principal investigator will elaborate the particle dynamics model in a coaxial electrode system with one electrode coated and predict improvement in the breakdown voltage profile and the breakdown probability of the compressed gas insulated transmission line (GITL) system in general. Experimental work will be needed to verify the results of the modeling. Experimental data will be obtained at the high voltage laboratory at Chalmers University of Technology, under the direction of Professor Stanislaw Gubariski. The proposed collaboration will enable verification of modeling outputs by conducting appropriate experiments. The impact of the proposed study will be in the broad area of energy infrastructure in urban USA by making compressed GIS/GITL technology more efficient, environmentally friendly, and easier to operate and maintain. The proposed project should be of interest to both utilities and manufacturers.