摘要
大型变压器绝缘状态检修是近年来的研究热点。综合分析近10 a发表的研究成果,发现多数研究集中在数据处理方面,较少研究变压器绝缘老化状态特征量的采样方法。在一个换油周期内,变压器绝缘电阻、局部放电参数、油中糠醛含量和空载电流等具有显著地随时间变化特征。在线连续采样或定期持续采样获取参数的变化特性是准确获取变压器绝缘状态的核心因素。其中,变压器特性绝缘参数线性增长可认为是绝缘正常老化的标志,此时的绝缘老化临界值可作为变压器大修的依据。对于绝缘特性非线性上升的情况,可将第2个拐点作为大修的依据。可能出现绝缘特性指标拐点的特性参数指标依次为局部放电PD相关参数、绝缘电导G、tan δ、糠醛含量、酸值、总烃以及绕组泄漏电流等。油中气体含量、水含量和整体变压器的温升可采用绝对值是否超标来判断绝缘状态。
The insulation maintenance of large transformers is a research hotspot in recent years, however, most studies focuses on the data processing method. Under this background, a sampling method of the insulation aging characteristics is proposed for transformers. For the fact that parameters of the transformer including the resistance, the partial discharges, the furfural content, and the no-load current are changed with time obviously, the variation characteristics of these parameters would be core factors to reflect the insulation status of transformers. Firstly, critical values of these insulation aging parameters are taken as the overhaul basis of transformers since the linear growth of insulating parameters is considered as the aging sign of transformers. Secondly, for those parameters increased with aging nonlinearly the second inflection point of the increasing curve can be used as the overhaul basis of transformers.In addition the possible parameters which have inflection point are parameters about partial discharge,insulating conductance,dielectric loss,furfural content,acid content,total hydrocarbon content,winding leakage current,etc.Besides,the dissolved gas content,water content in oil and temperature rise of transformer can also be used to judge the insulation condition of transformers.
作者
徐肖庆
朱宁
韦瑞峰
郑晓泉
张博
肖德健
XU Xiao-qing;ZHU Ning;WEI Rui-feng;ZHENG Xiao-quan;XIAO De-jian;ZHANG Bo(Kunming Power Supply Bureau,Yunnan Power Grid Co.Ltd.,Kunming 650000,China;State Key Laboratory of Power Equipment and Electrical Insulation,Xi'an Jiaotong University,Xi'an 710049,China)
出处
《电力科学与技术学报》
CAS
北大核心
2019年第4期189-193,共5页
Journal of Electric Power Science And Technology
关键词
变压器
状态检修
参数变化
绝缘特性
换油周期
transformer
condition based maintenance
parameter variation
insulating properties
oil replacement period
