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The frequency response analysis (FRA) is an effective technique to diagnose the mechanical deformations in a power transformer. Using the numerical indices is one of the methods proposed for the interpretation of the FRA results. Various indices have been proposed in the literature, but most of them are only based on the magnitude response of the FRA results. By contrast, this paper improves a number of the existing indices and defines a new index to include the phase response in the interpretation. The experimental data corresponding to different extents of the axial displacement and disc space variation show that including the phase response in an index increases its sensitivity. These results are also validated with simulation models of three transformers. Afterward, different uncertainties are introduced in the experiment, and it is shown that the new indices have also better performances against uncertainties in the FRA measurement. Although further studies are needed to settle the new indices, this research shows the early functionality and the potential of the phase information to improve the interpretation of the FRA results. 相似文献
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变压器绕组变形的频率响应分析法综述 总被引:17,自引:1,他引:17
目前对绕组频率响应的分析方法主要是基于幅频响应曲线的分析,因此从频段划分、幅频曲线特征的分析及曲线相似指数3方面综述了幅频响应曲线的研究现状,介绍了频率响应分析法的原理,从扫频范围的选择和影响测量的因素2方面讨论了绕组频率响应的测量,认为应建立原始的绕组频率响应数据库,在反映绕组变形程度的曲线相似指数研究方面有待于提出切实有效的量化标准。 相似文献
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Diagnosis Criterion of Abnormality of Transformer Winding by Frequency Response Analysis (FRA)
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SATORU MIYAZAKI YOSHINOBU MIZUTANI AKIRA TAGUCHI JUNICHI MURAKAMI NAOKAZU TSUJI MASAHIRO TAKASHIMA OSAMU KATO 《Electrical Engineering in Japan》2017,201(3):25-34
Frequency response analysis (FRA) is a powerful technique to detect internal abnormalities within power transformers. However, diagnosis criteria of power transformers by FRA have not been fully established yet. In this paper, a new evaluation method of degree of identification between two transfer functions is proposed. In the proposed method, a frequency window is employed and cross‐correlation factor is calculated with moving the window. Furthermore, the proposed method is applied to transfer functions of real transformers with or without some abnormalities. Based on this discussion, objective criteria for diagnosis of abnormalities of transformer windings by FRA are proposed. The proposed criteria are based on a few data of transformers with some abnormalities. Therefore, the proposed criteria are tentative and they would be improved by accumulation of further data. 相似文献
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振动频响法与传统频响法在变压器绕组变形检测中的比较 总被引:1,自引:0,他引:1
首先详细介绍了振动频响法(vibration frequency response analysis,VFRA)检测原理,并与传统频响法(frequency response analysis,FRA)进行了对比。然后对一台220 kV变压器绕组进行了多种人工故障设定,并利用振动频响法与传统频响法对所设故障进行对比检测分析。试验结果表明,振动频响法相比传统频响法对绕组预紧力下降、垫块脱落、幅向轻微变形等故障具有更高的检测灵敏度。 相似文献
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电力变压器绕组变形故障的测量分析与判断 总被引:11,自引:2,他引:11
采用频响分析法(FRA)测量电力变压器绕组的变形故障,具有灵敏度高、试验设备轻便、判断直观的优点。但是,频响分析法也受到诸多因素的影响,要求试验人员具有较高的测量分析能力。本文就测量方法和分析判断的一般原则提出了一些可行的原则,并对电力变压器绕组的变形故障的各种测试方法及其应用前景提出了一些建议。 相似文献
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《Electric Power Systems Research》2006,76(6-7):509-514
Mechanical forces due to short circuit currents especially near the power transformer will cause the axial displacement or radial deformation of transformer windings. Therefore, it is possible to have a transformer with mechanical faults in the electrical power system. Hence, it is necessary to design the insulation arrangement in order to get sufficient withstand against the impulse voltage distribution in case of such faults. In this paper, the effects of axial displacement on impulse and transferred voltage distribution are investigated with the help of two particular windings having the rated power of 1.3 MVA as a test object and its detailed model. The results show the significant influences of axial displacement on impulse voltage distribution so they should be considered in the design of insulation. 相似文献
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The paper discusses an improved modelling of transformer windings based on bacterial swarming algorithm (BSA) and frequency response analysis (FRA). With the purpose to accurately identify transformer windings parameters a model-based identification approach is introduced using a well-known lumped parameter model. It includes search space estimation using analytical calculations, which is used for the subsequent model parameters identification with a novel BSA. The newly introduced BSA, being developed upon a bacterial foraging behavior, is described in detail. Simulations and discussions are presented to explore the potential of the proposed approach using simulated and experimentally measured FRA responses taken from two transformers. The BSA identification results are compared with those using genetic algorithm. It is shown that the proposed BSA delivers satisfactory parameter identification and improved modelling can be used for FRA results interpretation. 相似文献
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电力变压器动稳定破坏的分析和对策 总被引:2,自引:0,他引:2
对大型电力变压器绕组在变压器发生外部短路时所受的辐向力和轴向力进行了分析和计算,比较了国内外不同的计算方法和得出的不同结果。 相似文献
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以一台QYS-R-(31500+25000)/220牵引变压器为研究对象,提出一种基于集总参数电路的考虑绕组间全电容参数的改进型频率响应模型,通过与实测曲线进行对比,验证了模型正确性;然后对变压器的牵引绕组和高压绕组分别进行了向内的曲翘变形和向外的鼓包变形这2种径向变形故障仿真,重点分析了不同变形故障对电容参数的影响;最后通过对变化的频率响应曲线进行分析。分析结果表明:牵引变压器牵引绕组和高压绕组发生径向变形故障时,特征诊断频带不同,但在各自的特征频带内频响曲线呈现相同的变化规律,即随着故障程度的增加,频率响应曲线向低频方向移动,并且幅值不断增大。 相似文献
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以240 MVA大型电力变压器低压螺旋绕组的实际结构尺寸为例,针对大型电力变压器螺旋线圈引起的扭转变形问题,采用数值积分的方法对变压器实际螺旋线圈中的轴向电流分量对漏磁场及扭转变形的影响进行了分析,给出了螺旋线圈在考虑轴向电流分量时辐向磁场沿线圈高度的分布规律. 相似文献
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介绍了应用频率响应分析法检测变压器绕组变形的两个实例.指出在检测中通过对前后频谱曲线的分析,能准确有效地发现变压器内部电气及机械事故隐患,对于变压器及电网的安全运行有着重要意义.但频率响应分析法不一定能够有效反映出变压器绕组变性发生单一扭动变形这类故障,绕组变形的诊断仍需使用多种试验手段综合分析和判断. 相似文献
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利用频域分段技术提高变压器绕组变形测试的准确性 总被引:5,自引:0,他引:5
目前判断变压器绕组变形主要采用频率响应分析法。由于不同频率段反映的变形信号不同,因此将频率段按谱振点个数平均划分三个区段。通过各频段上的相关性可以有助于提高判一变形的准确率。 相似文献
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《International Journal of Electrical Power & Energy Systems》2013,44(1):358-363
The health of power transformer is important for the reliability of electrical power grid. There are various methods of evaluating the frequency spectrum to confirm the presence of an incipient fault. So, the accuracy of FRA method suggested by many researchers for predictive defections, has been discussed; and the robustness (efficiency, simplicity and fast diagnosis) of the proposed 2LFW as a substitution diagnostic process has been detailed and proved. It should be noted that the proposal is general and can be applied to different transformer, without any comparison to a reference signal. Furthermore the diagnosis can be done even for transformers in operation mode (in service), thus avoiding economical losses. 相似文献
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Transfer function signatures are commonly used in condition monitoring analysis to give early indications of winding movement in power transformers. This paper presents a comparison of the use of trans-admittance (frequency response analysis, FRA), presently the industry standard, and characteristic impedance (transmission line diagnostics, TLD), a new method, as signatures for the detection of winding displacements in power transformers. To facilitate the comparison, a computer based winding model based on a multi-phase transmission line system was developed and different winding deformations were analyzed. The results show that TLD has a higher degree of sensitivity and can be used to augment the ability to classify different types of distortions currently diagnosed by FRA. 相似文献
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Frequency response analysis (FRA) is an effective technique to detect mechanical faults inside a power transformer. The FRA interpretation is normally carried out by comparing an FRA trace corresponding to a specific connection scheme with a fingerprint of its type. This paper, by contrast, proposes a novel method based on comparing FRA traces of different connection schemes recorded from the same winding to detect the mechanical deformations. In this contribution, the theoretical background is explained, and the experimental results are addressed to support the functionality of the proposed algorithm. Furthermore, a circuit model of the windings is created, and the simulation results are also used to validate the experimental measurements. Finally, two case studies describe the application of the new method in the condition assessment of transformers to achieve a more reliable decision. Although more research is needed to support the new applications, the early potential of the method is shown in this contribution. 相似文献