基于弹性力学-热力学的变压器铁芯磁致伸缩振动模型与松动故障诊断方法  

Magnetostrictive Vibration Model and Loosening Fault Diagnosis Method of Transformer Core Based on Elastodynamics-thermodynamics

作　　者：曹辰[1] 路敦林 徐博文 李晓龙 何龙 朱咏明 CAO Chen;LU Dunlin;XU Bowen;LI Xiaolong;HE Long;ZHU Yongming(School of Electrical Engineering,Shenyang University of Technology,Shenyang 110870,China;Department of Civil Engineering,Xi’an Jiaotong-Liverpool University,Suzhou 215123,China;Changji Power Supply Company,State Grid Xinjiang Electric Power Co.,Ltd.,Changji 831100,China)

机构地区：[1]沈阳工业大学电气工程学院,沈阳110870 [2]西交利物浦大学土木工程学院,苏州215123 [3]国网新疆电力有限公司昌吉供电公司,昌吉831100

出　　处：《高电压技术》2024年第5期2146-2157,I0038,共13页High Voltage Engineering

基　　金：国家自然科学基金(52107157);国网新疆电力有限公司科技项目(5230CJ230002);辽宁省教育厅科技项目(JYTMS20231208)。

摘　　要：为了准确分析变压器铁芯磁致伸缩现象,建立了弹性力学与热力学耦合的铁芯振动理论模型,并基于奇异性分解理论提出了松动故障诊断方法。首先通过耦合弹性力学中的应变能和热力学中的弹性自由能,建立了表征变压器铁芯多频段的磁致伸缩振动数学模型;接着考虑了基于弹性力学的非线性力-磁耦合机制的影响,建立了振动多频段多物理场仿真模型,得到了铁芯0~1000 Hz的多频段振动特性;然后搭建了变压器铁芯磁致伸缩振动采集平台,对10 kV变压器铁芯进行了振动监测试验。试验结果表明,铁芯振动除100 Hz基频以外,还含有200~600 Hz的振动信号,A、B相的实测结果分别为0.009、0.023 m/s^(2),仿真结果分别为0.009、0.023 m/s^(2),仿真与试验一致,验证了仿真模型的正确性;之后建立了铁芯松动故障模型,得到部分与完全松动状态下的振动特性。最后,对获得的振动信号进行故障诊断,以铁芯正常、部分松动、完全松动的不同状态信号为基础,提出了基于奇异性分解理论的方法,计算的特征量分别为0.0524、0.2822、1.5059,说明随着松动程度的逐渐加剧,特征量逐渐增大,验证了诊断方法的准确性。In order to accurately analyze the magnetostriction phenomenon of transformer cores,a theoretical model of core vibration coupled with elastodynamics and thermodynamics is established,and a method for diagnosing loosening based on singularity decomposition is proposed.Firstly,by coupling the strain energy in elastodynamics and the elastic free energy in thermodynamics,a mathematical model for magnetostrictive vibrations characterising the multi-band core of a transformer is developed.Secondly,the effect of a non-linear force-magnetic coupling mechanism based on elastic dynamics is taken into consideration,a vibration multi-band multi-physical field simulation model is established,and multi-band vibration characteristics of the core from 0 Hz to 1000 Hz are obtained.Thirdly,a magnetostrictive vibration acquisition platform for transformer cores is built and vibration monitoring tests are carried out on 10 kV transformer cores.The experimental findings show that,besides the primary frequency of 100 Hz,the core vibration also contains vibration signals from 200 Hz to 600 Hz,with the measured results of 0.009 m/s^(2) and 0.023 m/s^(2) for the A and B phases,and the simulation results of 0.009 m/s^(2) and 0.023 m/s^(2).The simulations agree with the experimental results and demonstrate the correctness of the simulation model.Afterwards,a core loosening fault model is developed to obtain the vibration characteristics in the partially and fully loosened state.Finally,the vibration signals are used to diagnose faults based on different states of the iron core,such as in normal,partially loose,and completely loose states.A method which is based on the singular decomposition theory is proposed,and characteristic values of 0.0524,0.2822,and 1.5059,respectively can be obtained.It is confirmed that,as the looseness worsens,the characteristic values increase,validating the feasibility of the diagnostic approach.

关 键 词：变压器 铁芯 磁致伸缩 振动信号 松动诊断 

分 类 号：TM407[电气工程—电器]