张涛 刘雅琴 杨文雁 张陈 任乔林 肖洒

摘 要：頻域介电谱（FDS）与水分含量的映射关系能有效评估油纸绝缘状态，为了直接利用频域介电特征量评估绝缘老化和受潮的方法，提出在特征频域段内采用介损积分值作为绝缘状态评估的特征参量，并实验研究了不同绝缘老化和受潮程度对频域介电谱和频域介损积分谱影响及其变化规律。研究结果表明：在10-3～102Hz范围内相对于频域介损，频域介损积分谱对油纸绝缘老化和受潮更为敏感，随着油纸绝缘老化程度和绝缘受潮的增大，介损积分均呈上升趋势，且曲线具有饱和值，该介损积分值可以量化评估油纸绝缘的状态;与绝缘老化相比，在10-3～102Hz范围内，频域介损积分值对绝缘纸的受潮更为敏感，其频域介损积分值更大。因此，提出的频域介损积分谱法为量化评估变压器绝缘状态提供新的研究思路。

关键词：频域介电谱;特征参量;频域介损积分谱;变压器;油纸绝缘

中图分类号：TM 41

文献标志码：A

文章编号：1007-449X（2019）07-0072-07

Abstract：The state of oilpaper insulation can be effectively assessed by the mapping relationship between the frequency domain spectrum and the moisture content. In order to directly use frequency domain dielectric characteristics to assesse insulation aging and dampness， the dielectric loss integral value was proposed as the characteristic parameter of insulation condition assessment in characteristic frequency domain. The effects of different insulation aging and dampness on dielectric spectrum in frequency domain and dielectric loss integral spectrum in frequency domain and its variation law were studied experimentally.Results show that in 10-3～102 Hz， the frequency domain spectrum of Stanδ than the frequency domain spectrum of tanδ is more sensitive in the change of aging state and moisture content， with the increase of aging degree and moisture content of oilpaper insulation， the dielectric loss integral tends to increase， and the curve has saturation value， which can quantitatively evaluate the state of oilpaper insulation. Compared with insulation aging， the dielectric loss integral value in frequency domain is more sensitive to moisture content of insulating paper in the range of 10-3～102 Hz， and its dielectric loss integral value in frequency domain is larger. Therefore， the proposed frequency domain dielectric loss integral spectrum method provides a new research idea for quantitative evaluation of transformer insulation state.

Keywords：frequency domain dielectric spectroscopy; characteristic parameter; the integral of FDS; transformer; oilpaper insulation

0 引 言

电力变压器作为电能传输和分配的核心和枢纽设备，其绝缘状态的好坏直接影响到电网的安全与稳定运行[1]。变压器是油纸组合绝缘系统，在长期不间断的运行中，易受电、热、水分和机械振动等多种应力的作用[2-3]，引起绝缘材料的受潮和老化，进而导致油纸绝缘微观结构及极化、损耗特性发生改变。因此，通过测量油纸绝缘系统的介电响应特性的变化，可以评估油纸绝缘系统的老化状态[4]。……