基于小波分析和时域介电谱的变压器油纸绝缘老化状态评估  

Status Assessment of Aging Condition of Transformer Oil-paper Insulation Based on Time Domain Dielectric Spectroscopy and Wavelet Analysis

作　　者：吴广宁[1] 夏国强 宋臻杰 高天山 高波[1] 

机构地区：[1]西南交通大学电气工程学院

出　　处：《高电压技术》2018年第1期226-233,共8页High Voltage Engineering

基　　金：中央高校基本科研业务费专项资金(2682015CX032)~~

摘　　要：为了研究变压器油纸绝缘老化特性，从而为变压器寿命评估作出指导，在实验室进行加速热老化实验，利用时域介电谱图对不同老化时间油纸试样的极化／去极化电流开展研究，结合小波分析理论对时域介电谱提出改进算法，并提取表征油纸各部分老化时间的特征量。结果表明：二次微分时域介电谱可以反映油纸绝缘的整体极化强度，测量时间1000s后介电谱出现峰值，且峰值随着老化时间的增加而增大；小波改进算法处理后的时域介电谱图的不同谱峰对应油纸绝缘3种主要极化类型，分别为油、油纸界面和绝缘纸内部极化；改进时域介电谱的不同峰值和峰值时间表征不同极化过程的强度和响应速度，且不同峰值与油、纸和油纸界面具有拟合优度很高的指数关系，可以考虑将改进时域介电谱不同谱峰作为表征油纸不同部分的老化特征量。In order to study the aging characteristics of oil-paper insulation, we prepared oil-paper samples at different aging time and studied the time-domain spectroscopy of samples by the polarization/depolarization current method. Moreover, we proposed an algorithm for improving time-domain spectroscopy based on wavelet transform theory. Then, the aging characteristic parameters of oil-paper insulation were extracted from the improved time-domain speetroscopy. Results show that time-domain spectroscopy can reflect the overall polarization of oil-paper insulation, and the spectrum peak will appear when measurement time exceeds 1 000 s. Then, after wavelet algorithm processing, the time domain di- electric spectrum can reflect three main polarization processes of oil-paper insulation （oil, paper and interface of oil-paper）. Peaks＇ values and times of improved time-domain spectroscopy correspond to the intensity and responding speed of different polarization processes, respectively. Finally, the values of spectrum peaks have a good exponential rela- tionship with aging times of oil-paper insulation which can be used as an aging characteristic parameters of different parts of oil-paper insulation.

关 键 词：油纸绝缘 极化/去极化电流 Meyer小波理论 特征量 时域介电谱 

分 类 号：TM855[电气工程—高电压与绝缘技术]