油纸绝缘水分平衡样品的制备及水分评估频域特征量提取  

Preparation of Oil-Paper Insulation Samples with Moisture Equilibrium and Frequency Domain Characteristic Parameters Extraction for Moisture Assessment

作　　者：高竣 廖瑞金[1] 王有元[1] 吕彦冬[2] 杨丽君[1] 刘捷丰[1] 汪可[3] 

机构地区：[1]重庆大学输配电装备及系统安全与新技术国家重点实验室,重庆400044 [2]阿尔斯通电网技术中心有限公司,上海201114 [3]中国电力科学研究院,北京100192

出　　处：《电工技术学报》2015年第18期196-202,共7页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金资助项目(51277187)

摘　　要：为了推动介质响应技术应用于现场电力变压器油纸绝缘状态评估,需要在实验室可靠地建立不同水分含量且水分平衡的油纸绝缘介质响应数据库。本文提出了一种不同水分含量油纸绝缘水分平衡样品的制备方法,深入分析了油纸水分迁移过程中与平衡后的频域介质响应,然后从中提取了反映纸板水分含量的频域特征参量,并初步给出了油纸绝缘水分平衡后的纸板水分含量与特征参量之间的量化关系,最后通过Karl Fischer滴定法验证了制备方法的可靠性。结果表明：随着绝缘纸板水分含量的增加,复电容的实部C′在10^-3-100 Hz范围内明显增大,介质损耗tan？曲线与复电容虚部C″曲线均向高频方向移动;介质损耗因数tanδ、复电容实部C′、虚部C″在特征频率处（f=10^-3Hz、10^-2Hz、10^-1Hz、100Hz）均与绝缘纸板的水分含量存在明显的函数关系;本文所提出的方法可以较准确地制备出不同水分含量且达到水分平衡的油纸绝缘样品。In order to promote the applicaton of the frequency-domain dielectric spectroscopy（FDS） to the nondestructive diagnosis of oil-paper insulation states of transformer, it is necessary to establish a reliable dielectric response database of oil-paper insulation with different equilibrium moisture contents in the laboratory. In this paper, a new preparation method for oil-paper insulation samples with different equilibrium moisture contents is proposed and the transient and stable frequency domain dielectric responses of oil-paper insulation during the migration process of moisture between oil and pressboard are deeply investigated. In the meanwhile, the quantitative relationships between moisture and characteristic parameters extracted from frequency domain dielectric properties are established. Finally, the actual moisture content of pressboards is measured by the Karl Fischer moisture meter to verify the validity of the proposed preparation method. Results show that in the migration process of moisture between oil and pressboard, the real part C′ of the complex capacitance increase obviously within 10^-3-100 Hz, while the imaginary part C″ of the complex capacitance and the dielectric loss parameter tan δ present a clear tendency towards the high frequency region. The clear functional relationships between tanδ, C ′, C ″ and the moisture content in the pressboard are respectively observed in their characteristic frequency points（ f=10^-3Hz, 10^-2Hz, 10^-1Hz, 100Hz）. The sample preparation method proposed in this paper can be used to accurately manufacture the pressboards with expected equilibrium moisture contents.

关 键 词：频域介质响应 油纸绝缘 水分平衡 介质损耗因数 特征频率 

分 类 号：TM855[电气工程—高电压与绝缘技术]