换流变压器油纸绝缘多因子老化介电响应评估方法  

Dielectric Response Evaluation Method for Multi-factor Aging of Converter Transformer Oil-paper Insulation

作　　者：刘骥[1] 程炜超 张明泽[1] 马兴明 贾海峰 庄伟韬 LIU Ji;CHENG Weichao;ZHANG Mingze;MA Xingming;JIA Haifeng;ZHUANG Weitao(Key Laboratory of Engineering Dielectrics and Its Application,Ministry of Education,Harbin University of Science and Technology,Harbin 150080,China;State Grid Beijing Huairou Power Supply Company,Beijing 101400,China;Daqing Power Supply Bureau,Heilongjiang Power Grid Co.,Ltd.,Daqing 163458,China)

机构地区：[1]哈尔滨理工大学工程电介质及其应用教育部重点实验室,哈尔滨150080 [2]国网北京怀柔供电公司,北京101400 [3]国网黑龙江省电力有限公司大庆供电公司,大庆163458

出　　处：《高电压技术》2022年第5期1684-1694,共11页High Voltage Engineering

基　　金：国家重点研发计划(2017YFB0902705);国家自然科学基金(51977051)。

摘　　要：换流变压器运行中承受电热振动多因子作用,其油纸绝缘老化过程复杂,如何评价多因子联合作用下换流变压器绝缘老化特性,是亟待解决的运维关键问题。为此采用时域介电响应技术,通过多因子加速老化试验获得的不同老化程度油纸绝缘试样,测得不同老化程度油纸绝缘模型的极化和去极化电流曲线,根据试验结果计算得到随时间变化的电导电流,从中提取出呈指数规律衰减的吸收电流部分;其次对吸收电流进行积分计算得到吸收电荷量的参数值,建立稳态吸收电荷量与聚合度之间的关系,通过吸收电荷量的相对增长率为绝缘状态进行划分等级;最后将吸收电流对数化处理并绘制线性直谱线,提取出直谱线斜率的绝对值作为特征量评估油纸绝缘的老化状态,为换流变绝缘老化状态的评估提供了理论基础。The converter transformer is subjected to multiple factors such as the actions of electricity,heat and vibration during operation,and its oil-paper insulation aging process is complicated.How to evaluate the insulation aging characteristics of converter transformers under the combined action of multiple factors is a key operation and maintenance problem that needs to be solved urgently.In this paper,the time-domain dielectric response technology is used to obtain oil-paper insulation samples with different aging degrees through accelerated multi-factor aging tests,and the polarization and depolarization current curves of oil-paper insulation models with different aging degrees are measured.Moreover,the changes of electrical conduction current with time are calculated according to the test results,among which the absorption current that decays exponentially is extracted.Secondly,the absorbed current is integrated to calculate the parameter value of the absorbed charge,the relationship between the steady-state absorbed charge and the degree of polymerization is established,and the insulation state is classified by the relative growth rate of the absorbed charge.Finally,the linear straight spectrum line is drawn by the logarithmic processing of the absorbed current,and the absolute value of the slope of the straight spectrum line is extracted as the characteristic quantity to evaluate the aging state of oil-paper insulation,which provides a theoretical basis for the evaluation of the aging state of the converter transformer insulation.

关 键 词：油纸绝缘 多因子联合老化 介电响应 吸收电荷量 线性直谱线 

分 类 号：TM721.1[电气工程—电力系统及自动化] TM41