特高压盆式绝缘子裂纹缺陷放电研究

发布时间：2018-06-02 23:02

本文选题：特高压GIS + 盆式绝缘子　；参考：《华北电力大学》2014年硕士论文

【摘要】：特高压电网是未来电网战略发展的重要方向,特高压电网建设中,开关设备均选用GIS或者HGIS。晋东南—南阳—荆门1000kV特高压交流试验示范工程已经正式投运3年来,已经发现2支存在裂纹缺陷的盆式绝缘子,而现场特高频局放检测装置未能提前预警。特高压盆式绝缘子作为气体绝缘组合开关(GIS)的核心零部件,其绝缘性能直接关系到电网的安全稳定运行。目前国内外对于特高压盆式绝缘子状态监测和缺陷的早期预警技术仍不成熟,现有的局放检测方法对特高压盆式绝缘子缺陷类型诊断的适用性仍不清晰。因此,通过有限元分析方法研究不同形式裂纹缺陷对特高压盆式绝缘子电场强度分布特性的影响,并通过局放检测的方法研究现有检测手段对特高压盆式绝缘子裂纹缺陷的适用性,以及特高压盆式绝缘子裂纹缺陷的放电发展规律,对于提高现场状态检测的准确性可靠性,保障电网安全稳定运行具有十分重要意义。本文为了研究裂纹对特高压盆式绝缘子的电场分布的影响,基于有限元数值分析的方法,建立了特高压盆式绝缘子的静电场分析模型,对多种电压等级无裂纹缺陷的盆式绝缘子电场分布进行了计算,并对存在裂纹缺陷的特高压盆式绝缘子的电场分布进行了计算。通过仿真得到了特高压盆式绝缘子在工作电压下的最大场强,最小场强,平均场强；存在裂纹缺陷状态下裂纹的厚度、位置、发展方向对绝缘子电场分布的影响。本文为了对特高压盆式绝缘子裂纹缺陷开展实验研究,对特高压盆式绝缘子裂纹缺陷放电环境进行了模拟,综合考虑了SF6气体、环氧树脂材料特性、绝缘子电场分布、电压等级等因素,在252kV GIS内搭建了特高压盆式绝缘子裂纹缺陷放电试验平台。并设计加工了特高压盆式绝缘子裂纹缺陷试验模型。本文为了对特高压盆式绝缘子裂纹缺陷放电特性进行试验研究,设计了多种不同形式的盆式绝缘子裂纹缺陷模型,综合考虑了裂纹的厚度、方向、位置等影响因素,使用特高频法、常规脉冲电流法两种方法对放电现象进行检测,分析两种方法的检测效果,并对放电规律进行了总结。
[Abstract]:UHV power grid is an important direction in the future development of grid strategy. In the construction of UHV power grid, GIS or HGIs is used as the switchgear. In the past three years, two basin insulators with crack defects have been found in the 1000kV UHV test and demonstration project in southeast Shanxi, Nanyang and Jingmen, and the UHF PD detection device in the field has not been able to give early warning. As the core parts of GISs, the insulation performance of UHV basin insulators is directly related to the safe and stable operation of power grid. At present, the status monitoring and early warning technology of UHV basin insulators are still immature, and the applicability of existing partial discharge detection methods to the diagnosis of UHV basin insulators defect types is still unclear. Therefore, the influence of crack defects in different forms on the distribution of electric field intensity of UHV basin insulators is studied by means of finite element analysis (FEM). By means of partial discharge detection, the applicability of existing detection methods to crack defects in UHV basin insulators and the discharge development law of crack defects in UHV basin insulators are studied, which can improve the accuracy and reliability of field state detection. It is very important to ensure the safe and stable operation of power grid. In order to study the effect of crack on electric field distribution of UHV basin insulator, the electrostatic field analysis model of UHV basin insulator is established based on finite element numerical analysis method. The electric field distribution of basin insulator with various voltage levels without crack defects is calculated, and the electric field distribution of ultra high voltage basin insulator with crack defect is calculated. The maximum, minimum and average field strength of the UHV basin insulator under the working voltage and the influence of the crack thickness, position and development direction on the insulator electric field distribution under the condition of crack defect are obtained by simulation. In order to study the crack defect of UHV basin insulator, the discharge environment of crack defect in UHV basin insulator is simulated in this paper. The characteristics of SF6 gas, epoxy resin material and the electric field distribution of insulator are considered synthetically. Based on the voltage level and other factors, an ultra high voltage (UHV) basin-type insulator crack discharge test platform was built in 252kV GIS. An experimental model for crack defects of an UHV basin insulator is designed and manufactured. In this paper, in order to study the discharge characteristics of crack defect in UHV basin insulator, several kinds of crack defect models of basin insulator are designed, and the influence factors such as crack thickness, direction and position are considered synthetically. UHF method and conventional pulse current method are used to detect the discharge phenomenon. The detection results of the two methods are analyzed and the discharge law is summarized.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM855;TM216

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