【作者】 端木林楠；

【导师】 文远芳；

【作者基本信息】 华中科技大学 ， 高电压与绝缘技术， 2009， 硕士

【摘要】 瓷质绝缘子在线检测方法的研究对于提高电力系统的安全可靠性运行具有十分重要的意义。本文基于大量人工污秽试验,详细研究了外施电压下绝缘子泄漏电流与盐密、灰密、温湿度的关系。利用脉冲电流法检测系统对不同绝缘子在不同电压下的脉冲电流特性进行了研究。介绍了脉冲电流法的检测系统的组成,对试品绝缘子的脉冲电流特性进行了研究,实验结果表明:试品绝缘子局放脉冲能量主要出现在工频相位的60o ~120o和240o ~ 300o之间。且随着绝缘子劣化程度的加深脉冲电流的幅值、脉冲个数和产生相位的范围都增大。实测数据中不可避免的存在高频噪声干扰,基于小波分析理论用matlab编程,通过小波分解和小波重构实现了对实验所获得数据中的高斯白噪声的抑制,使数据更加接近其实际值,为相应的数据处理和分析提供了保障。绝缘子表面的污秽度和潮湿程度决定了其在外施电压下的泄漏电流的性质,为了研究这种关系,在大量人工雾室实验数据的基础上,考查了绝缘子泄漏电流的谐波分量和相角差φ随表面污秽度、温湿度的变化规律。实验结果表明随着污秽度和相对湿度的增大,泄漏电流中的3次谐波占基波比例有所增加,在干燥污秽情况下,绝缘子呈容抗特性;湿润污秽情况下,绝缘子呈阻抗特性。更多还原

【Abstract】 The study of on-line detecting method for porcelain insulators is important to improve the safety of the power system.Based on the results of a large numbers of artificial contamination experimentation, the interaction of leakage current (under running voltage) and ESDD, CSDD, RH, temperature is analyzed in detail. In this paper, on-line detection for different insulators based on pulse current method is studied. The constituent parts and the realization of the detecting system are introduced. In laboratory, the partial discharge pulse current characteristics of the composite insulators have been studied. The results indicate that partial discharge pulses mainly occur between 60o ~120o and 240o ~ 300o in power frequency phrase. The amplitude of impulse current, the number of the impulse and the phase scope where occurs increase along with the development of the insulator deterioration.The laboratory data is inevitably influenced by high-frequency noise. Based on the wavelet theory, the matlab is used to de-noise the Gaussian white noise by wavelet decomposition and wavelet reconstruction, hence the data approaches the actual value. The following data processing and analysis is guaranteed.The leakage current characteristic under certain voltage is determined by the contamination, relative humidity and temperature. Based on the results of a large numbers of artificial contamination experimentation, the relation between leakage current harmonic component, the phase angle and the surface contamination, relative humidity, temperature is studied. The experiment results state that as the contamination and the RH increases, the ratio of the triple-harmonic in first-harmonic of the leakage current is also rising. The insulator is capacitive reactance in the dry contaminated environment and impedance in the wet contaminated environment.更多还原