特高压换流变压器阀侧套管电热场分布特性研究
发布时间：2019-06-24 10:03
【摘要】：特高压输电是解决我国能源和电力发展的治本之策。近年来,直流输电因其"输送容量大,输电距离远"的优点而被我国输电工程所广泛采用。换流变压器阀侧套管是直流输电系统中的关键器件,其性能的稳定性直接关系到直流输电系统的安全稳定运行。工作电压形式复杂和直流工程中电流巨大的双重影响导致换流变阀侧套管故障频发。因此,本文通过仿真计算、实验研究等手段分析了换流变阀侧套管运行中电热场的分布规律;通过模拟套管典型故障,研究了套管故障状态下的放电特征以及电场特征,可为发现套管绝缘的薄弱区域,研究套管故障的产生与发展机理提供参考。基于干式SF6换流变压器阀侧套管实际结构尺寸,运用有限元仿真软件INFOLYTICA建立换流变压器套管仿真模型,计算在直流、交流、极性反转等典型激励作用下换流变压器套管的电场,以此对比分析了不同类型激励下换流变阀侧套管的电位、电场分布规律,并讨论了套管电容芯子中的铝箔对于套管电场的优化作用。针对直流输电工程中电流等级进一步提高,换流变阀侧套管过热情况严重的问题。通过运用仿真软件SIMULINK计算了换流变阀侧套管所承受电流的频谱特征,并通过现场测量调研了负荷高峰期换流变压器油的温度情况,以此掌握了换流变阀侧套管运行时的工作电流、温度等环境条件。进一步通过设计模拟换流变阀侧套管运行环境的大电流温升试验平台,对换流变压器套管样品开展了温升试验。通过合理地制定温升试验程序,在套管电容芯子轴向、径向关键位置布置温度探头,获得了实验中套管不同位置的温度结果。以此研究了套管样品在温升实验中的热态变化规律以及换流变阀侧套管在运行时的稳态温度场分布规律。针对换流变阀侧套管在实际运行中的故障发生情况。设计、加工了模拟芯体电容屏击穿、芯体中混入金属颗粒、芯体中混入气泡、芯体中产生裂纹等四种典型故障的套管模型。并在实验室条件下模拟直流套管运行环境对四类故障套管模型开展了局部放电试验研究,统计了四类故障下套管模型放电次数与单次放电量之间的关系,分析了直流套管在四类典型故障下的放电特征,并结合电场仿真分析了四类典型故障套管的电场分布特征,为研究直流套管故障产生与发展的机理提供了参考。
[Abstract]:UHV transmission is a fundamental solution to the development of energy and power in China. In recent years, DC transmission has been widely used in transmission projects in China because of its advantages of large transmission capacity and long transmission distance. Valve side casing of converter transformer is the key device in HVDC system, and its performance stability is directly related to the safe and stable operation of HVDC system. The complex form of working voltage and the great influence of current in DC engineering lead to frequent failure of casing on the side of flow changing valve. Therefore, by means of simulation calculation and experimental research, the distribution law of electrothermal field in casing operation on the side of valve changing valve is analyzed in this paper, and the discharge characteristics and electric field characteristics under casing fault state are studied by simulating typical casing fault, which can provide reference for finding the weak area of casing insulation and studying the generation and development mechanism of casing fault. Based on the actual structure size of valve side casing of dry SF6 converter transformer, the simulation model of converter transformer casing is established by using finite element simulation software INFOLYTICA. The electric field of converter transformer casing under typical excitation, such as DC, AC, polarity reversal and so on, is calculated, and the distribution law of potential and electric field of converter valve side casing under different types of excitation is compared and analyzed. The optimization effect of aluminum foil in casing capacitance core on casing electric field is also discussed. In order to further improve the current level and overheat the casing on the side of the flow valve in DC transmission project, the overheating of the casing on the side of the flow valve is serious. The spectrum characteristics of the current borne by the flow valve side casing are calculated by using the simulation software SIMULINK, and the temperature of the converter transformer oil at the peak load period is investigated by field measurement, so as to master the working current, temperature and other environmental conditions of the flow valve side casing. Furthermore, the temperature rise test of converter transformer casing sample was carried out by designing a high current temperature rise test platform to simulate the operating environment of the casing on the side of the converter valve. By reasonably formulating the temperature rise test program and arranging the temperature probe in the axial and radial key positions of the casing capacitance core, the temperature results of the casing at different positions in the experiment are obtained. Based on this, the thermal state variation of casing samples in temperature rise experiment and the steady state temperature field distribution of casing on the side of flow changing valve are studied. In view of the failure of the casing on the side of the flow changing valve in actual operation. Four typical fault casing models are designed and fabricated, which simulate the breakdown of capacitance screen in the core, the metal particles in the core, the bubbles in the core and the cracks in the core. The partial discharge test of four kinds of fault casing models is carried out under laboratory conditions to simulate the operating environment of DC casing. The relationship between discharge times and single discharge capacity of four kinds of fault casing models is counted, the discharge characteristics of DC casing under four typical faults are analyzed, and the electric field distribution characteristics of four kinds of typical fault casing are analyzed by electric field simulation. It provides a reference for the study of the mechanism of DC casing fault generation and development.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM721.1;TM41
[Abstract]:UHV transmission is a fundamental solution to the development of energy and power in China. In recent years, DC transmission has been widely used in transmission projects in China because of its advantages of large transmission capacity and long transmission distance. Valve side casing of converter transformer is the key device in HVDC system, and its performance stability is directly related to the safe and stable operation of HVDC system. The complex form of working voltage and the great influence of current in DC engineering lead to frequent failure of casing on the side of flow changing valve. Therefore, by means of simulation calculation and experimental research, the distribution law of electrothermal field in casing operation on the side of valve changing valve is analyzed in this paper, and the discharge characteristics and electric field characteristics under casing fault state are studied by simulating typical casing fault, which can provide reference for finding the weak area of casing insulation and studying the generation and development mechanism of casing fault. Based on the actual structure size of valve side casing of dry SF6 converter transformer, the simulation model of converter transformer casing is established by using finite element simulation software INFOLYTICA. The electric field of converter transformer casing under typical excitation, such as DC, AC, polarity reversal and so on, is calculated, and the distribution law of potential and electric field of converter valve side casing under different types of excitation is compared and analyzed. The optimization effect of aluminum foil in casing capacitance core on casing electric field is also discussed. In order to further improve the current level and overheat the casing on the side of the flow valve in DC transmission project, the overheating of the casing on the side of the flow valve is serious. The spectrum characteristics of the current borne by the flow valve side casing are calculated by using the simulation software SIMULINK, and the temperature of the converter transformer oil at the peak load period is investigated by field measurement, so as to master the working current, temperature and other environmental conditions of the flow valve side casing. Furthermore, the temperature rise test of converter transformer casing sample was carried out by designing a high current temperature rise test platform to simulate the operating environment of the casing on the side of the converter valve. By reasonably formulating the temperature rise test program and arranging the temperature probe in the axial and radial key positions of the casing capacitance core, the temperature results of the casing at different positions in the experiment are obtained. Based on this, the thermal state variation of casing samples in temperature rise experiment and the steady state temperature field distribution of casing on the side of flow changing valve are studied. In view of the failure of the casing on the side of the flow changing valve in actual operation. Four typical fault casing models are designed and fabricated, which simulate the breakdown of capacitance screen in the core, the metal particles in the core, the bubbles in the core and the cracks in the core. The partial discharge test of four kinds of fault casing models is carried out under laboratory conditions to simulate the operating environment of DC casing. The relationship between discharge times and single discharge capacity of four kinds of fault casing models is counted, the discharge characteristics of DC casing under four typical faults are analyzed, and the electric field distribution characteristics of four kinds of typical fault casing are analyzed by electric field simulation. It provides a reference for the study of the mechanism of DC casing fault generation and development.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM721.1;TM41
【相似文献】
相关期刊论文 前10条
1 ;天威保变第三台换流变压器一次试验成功[J];变压器;2009年01期
2 张杰;罗隆福;张志文;李勇;李季;赵志宇;;新型换流变压器建模及故障计算[J];高电压技术;2009年12期
3 李溪;;大型换流变压器的移位方法[J];沿海企业与科技;2012年10期
4 文，
本文编号：2504978
本文链接：https://www.wllwen.com/kejilunwen/dianlidianqilunwen/2504978.html
