气体放电试验装置的研制及其应用

发布时间：2018-03-31 01:20

本文选题：气体绝缘　切入点：耐受压力　出处：《上海交通大学》2015年硕士论文

【摘要】：气体是一种实用的绝缘介质,不管是中压领域的环网柜还是高压领域的气体绝缘组合电器,都需要气体绝缘介质。而SF6气体是一种使用量很大的气体绝缘介质,在中压领域特别是12k V环网柜市场上占有大部分份额。但近年来的研究发现SF6是温室效应气体之一,是影响全球变暖的重要因素,因此人们着手研究新的绝缘介质取代SF6。气体绝缘水平的高低常通过气体放电试验来验证,因此,我们很有必要研发一套气体放电装置来研究SF6混合气体以及环保型气体的放电特性,并为该气体的推广做好前期技术储备。本文研究气体放电特性的思路是基于以下三种典型的电场:均匀电场、稍不均匀电场和极不均匀电场。三种电场模型可通过一定条件下的板-板、球-球、针-板电极来实现,而气体放电不仅包括气体本体放电还包括沿着绝缘结构表面的放电。因此,一套完整的放电装置要能实现放电现象的观测,不应在试验过程中造成设备表面爬电;设备在试验过程中因电击损坏。其次,还应具有抽真空、充放气、电极切换、间距调节等基本功能。再次,气体放电试验装置也是一种承压容器,要满足压力设备安全使用要求,法兰壁厚、封口连接、压力显示、密封保压、超压泄放等要求必须得到保证。本文通过查阅国内外资料,对气体绝缘设备做了充分的分析和比较,指出其优缺点。通过对罐体壁厚和承压能力的详细计算,确定了罐体的外形尺寸;通过比较几种调节电极方案的优缺点选择了一种动密封方案;通过对压力容器其密封的关键参数研究确定了与密封有关的尺寸及配合间隙。在进行装置的电气结构设计时,首先确定了高压引入端绝缘子/套管的外形尺寸、闪络距离。借助ANSYS仿真软件分析了各种电极情况下的电场分布,并根据仿真结果对电极结构、高压套管的外形和尺寸做了优化。最后研制成功了一整套结构较合理、功能较齐全的气体绝缘试验装置,为环保型气体的研究做好准备。最后利用本套装置进行SF6气体的放电试验,及SF6/N2混合气体的绝缘试验,将试验结果和前人研究的结论对比,所测数据基本吻合,所有试验均达到了预期效果,从而证明用本套装置进行环保气体绝缘方面的研究是完全合适的。
[Abstract]:Gas is a practical insulating medium, whether in the field of medium voltage ring cabinets or in high voltage field gas insulation composite appliances, gas insulation medium, and SF6 gas is a kind of gas insulation medium, In the field of medium voltage, especially in the market of 12kV ring cabinets, it has been found in recent years that SF6 is one of the gases of Greenhouse Effect and an important factor influencing global warming. Therefore, people began to study the replacement of SF6with new insulating dielectrics. The level of gas insulation is often verified by gas discharge tests. It is necessary to develop a set of gas discharge devices to study the discharge characteristics of SF6 mixtures and environmentally friendly gases. In this paper, the idea of studying the characteristics of gas discharge is based on the following three typical electric fields: uniform electric field, The three kinds of electric field models can be realized by plate plate, ball ball, needle plate electrode under certain conditions. The gas discharge includes not only the discharge of the gas body but also the discharge along the surface of the insulating structure. Therefore, a set of complete discharge devices should be able to realize the observation of the discharge phenomenon and should not cause the surface creeping of the equipment in the course of the test. The equipment is damaged by electric shock during the test. Secondly, it should also have the basic functions of pumping vacuum, filling and discharging gas, switching electrodes and adjusting the spacing. Thirdly, the gas discharge test device is also a kind of pressure vessel. In order to meet the requirements of safe use of pressure equipment, the requirements of flange wall thickness, sealing connection, pressure display, sealing keeping pressure, overpressure releasing and so on must be guaranteed. The gas insulation equipment is analyzed and compared, and its advantages and disadvantages are pointed out. Through the detailed calculation of the wall thickness and pressure bearing capacity of the tank, the external dimensions of the tank are determined. By comparing the advantages and disadvantages of several kinds of regulating electrode schemes, a dynamic sealing scheme is selected, and the dimensions and matching clearance related to the seal are determined by studying the key parameters of the seal of the pressure vessel. The shape size and flashover distance of the insulator / casing at the high voltage inductor end are first determined. The electric field distribution under various electrode conditions is analyzed with the help of ANSYS simulation software, and the electrode structure is analyzed according to the simulation results. The shape and size of high voltage casing are optimized. Finally, a set of gas insulation test equipment with reasonable structure and complete function has been developed. Finally, the discharge test of SF6 gas and the insulation test of SF6/N2 mixture gas are carried out by using this device. The experimental results are compared with the conclusions of previous studies, and the measured data are in good agreement with each other. All the experiments have achieved the expected effect, which proves that the research on environmental gas insulation with this device is completely suitable.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM21

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