基于介电频域特性的套管绝缘状态评估研究

发布时间：2018-05-02 09:06

本文选题：介电频谱 + 高压套管　；参考：《大连理工大学》2015年硕士论文

【摘要】：变压器套管作为电网核心设备——变压器的关键组件,在运行过程中,会受到高压、电磁、温度等运行环境的影响,其绝缘会发生劣化和性能下降,导致电力变压器发生故障。套管的事故不仅会导致自身及变压器的损坏,还会导致高压输电系统的中断,给社会和国家造成巨大的经济损失。因此,高压变压器套管的绝缘状态检测与状态评估对电网安全运行具有保障和预防作用,具有十分重要意义。频域介电响应法虽然在电力绝缘检测中得到了广泛的研究与应用,但鲜有将频域介电响应法应用到高压套管的绝缘状态检测与评估。本论文应用频域介电响应法对电容式油纸绝缘变压器套管进行绝缘检测与评估研究。首先,根据油纸绝缘极化理论建立高压套管油纸绝缘结构的介电频域响应仿真模型并对其进行仿真研究,然后,设计了电容式油纸绝缘套管的物理模型,进行热老化试验研究,并对不同老化程度的套管被试品进行一些列频域介电谱曲线(FDS)测试。找出不同老化程度的套管被试品的电容量C及介质损耗因数tanδ频域谱线与绝缘老化时间及绝缘老化状态的对应关系,为介质频域响应分析法在电容式油纸高压套管的绝缘检测与评估应用,探究了一种新的方法。研究获得主要成果如下：(1)通过深入研究油纸电容式高压套管结构及油纸绝缘介电频域响应理论,构建了高压套管油纸绝缘结构Debye仿真模型。(2)通过仿真与热老化试验分析,获得高压套管电容量C频域谱曲线随着绝缘状态的劣化而升高的变化规律。介质损耗因数频域谱曲线只有在1Hz处能够有规律的随绝缘状态的劣化而发生对应改变。(3)经仿真与试验研究发现,电容量C频域谱曲线能用f(x)=a*exp(b*x)+c*exp(d*x)函数进行很好的拟合。(4)试验研究和分析表明：油纸绝缘套管电容量C的频域谱曲线的积分与老化时间或绝缘纸聚合度的倒数差成二次函数关系。为应用电容量频域谱曲线研究其套管油纸绝缘结构的绝缘状态提供一种新方法。
[Abstract]:As the key component of transformer, transformer bushing will be affected by high voltage, electromagnetic, temperature and other operating environments during operation, and its insulation will deteriorate and its performance will decline, which will lead to power transformer failure. The accident of casing will not only cause damage to itself and transformer, but also lead to the interruption of HV transmission system, which will cause huge economic losses to society and country. Therefore, the insulation state detection and state evaluation of high-voltage transformer bushing is of great significance for the safe operation of power network. Although the frequency-domain dielectric response method has been widely studied and applied in the electric insulation detection, the frequency-domain dielectric response method has rarely been applied to the insulation state detection and evaluation of high-voltage sleeving. In this paper, the dielectric response method in frequency domain is used to detect and evaluate the insulation of capacitive oil-paper insulated transformer casing. First of all, according to the theory of oil-paper insulation polarization, the dielectric frequency domain response simulation model of high-voltage sleeving oil-paper insulation structure is established and simulated. Then, the physical model of capacitive oil-paper insulating sleeving is designed, and the thermal aging test is carried out. A number of dielectric spectrum curve lines (FDS) were measured for the casing samples with different aging degrees. The relationship between capacitance C and dielectric loss factor tan 未 frequency-domain spectral lines, insulation aging time and insulation aging state were found out. In order to apply the dielectric frequency domain response analysis method to the insulation detection and evaluation of capacitive oil paper high voltage sleeving, a new method is explored. The main results are as follows: (1) through the in-depth study on the structure of oil-paper capacitive high-voltage casing and the theory of dielectric frequency response of oil-paper insulation, the Debye simulation model of oil-paper insulation structure of high-voltage casing is constructed. The C-frequency spectrum curve of high voltage bushing is obtained, which increases with the deterioration of insulation state. The frequency domain spectrum curve of dielectric loss factor can change regularly with the deterioration of insulation state only at 1Hz. The experimental study and analysis of the C frequency domain spectrum curve of oil-paper insulating sleeving can be carried out by using the function of f ~ (x) ~ (X) ~ (() ~ (?) ~ (4). The results show that the integration of the spectrum curve in frequency domain of oil-paper insulating sleeve C has a quadratic function with the ageing time or the reciprocal difference of the degree of polymerization of insulator paper. It provides a new method to study the insulation state of the oil-paper insulation structure of the casing by using the frequency domain spectrum curve of capacitance.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM403;TM216.5

【参考文献】