基于振动频谱分析和总谐波畸变率的电力变压器故障诊断方法研究  

Research on Fault Diagnosis of Power Transformers Based on Spectral Analysis ofVibration Signals and Total Harmonic Distortion

作　　者：刘胜军 孙志鹏 沈辰 龚乐乐 LIU Shengjun;SUN Zhipeng;SHEN Chen;GONG Lele(Baoding Electric Power Supply Company,State Grid Hebei Electric Power Company,Baoding 071051,Hebei,China;College of Electrical Engineering,Northeast Electric Power University,Jilin 132012,Jilin,China)

机构地区：[1]国网河北省电力公司保定供电分公司,河北保定071051 [2]东北电力大学电气工程学院,吉林吉林132012

出　　处：《电网与清洁能源》2021年第3期86-91,共6页Power System and Clean Energy

基　　金：河北省电力公司科技项目(SGHEBDOOYJJS-1800491)。

摘　　要：利用振动法对电力变压器进行监测是国内外研究的热点。目前,人们常采用振动信号的基频幅值作为诊断变压器特征指标,而变电站现场基频幅值受多种因素影响,这种状况导致了振动法较少应用于变电站现场。该文对实验室和变电站变压器振动信号进行频谱分析,采用总谐波畸变率作为特征指标诊断变压器运行状态。实验结果表明,空载时铁芯和箱体振动信号基频幅值与电压平方近似呈线性,短路时绕组和箱体振动信号基频幅值与电流平方近似呈线性。绕组变形和铁芯松动时,基频幅值和谐波含量显著增加。变压器运行年限越长,总谐波畸变率越大,当总谐波畸变率超过20时,变压器存在绕组或铁芯故障。Using vibration analysis to monitor power transformers has become a research hotspot both at home and abroad.At present,fundamental frequency amplitudes of vibration signals are commonly used as the characteristic index to diagnose power transformers,but these fundamental frequency amplitudes are affected by many factors in substations,therefore vibration analysis is seldom applied in real substation sites.In this paper,the spectral analysis of vibration signals of laboratory and substation transformers is conducted,and total harmonic distortions are used as the characteristic index to diagnose power transformers.The experimental results show that the fundamental frequency amplitudes of the core and tank vibration signals are nearly linear with voltage squared when open-circuited,and the fundamental frequency amplitudes of the winding and tank vibration signals are nearly linear with current squared when short-circuited.When there are winding deformations and core looseness,the fundamental frequency amplitudes and harmonic contents are dramatically increased.The total harmonic distortions are increased with the increase of operating life.When the total harmonic distortions exceed 20,the power transformers have winding deformations and core looseness faults.

关 键 词：电力变压器 振动 频谱分析 绕组变形 铁芯松动 总谐波畸变率 

分 类 号：TM85[电气工程—高电压与绝缘技术]