A Comprehensive Analysis of Windings Electrical and Mechanical Faults Using a High-Frequency Model
A Comprehensive Analysis of Windings Electrical and Mechanical Faults Using a High-Frequency Model
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DOI：
10.3390/en13010105
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发表时间：
2019-12
期刊：
影响因子：
3.2
通讯作者：
M. Tahir;S. Tenbohlen
中科院分区：
文献类型：
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作者：
M. Tahir;S. Tenbohlen
电力变压器频率响应分析（FRA）的测量程序在IEC和IEEE标准中有很好的记录。但是，对森林资源评估结果的解释仍远未达到公认的方法，而且仅限于专家的分析。难题在于，目前可用的案例研究有限，无法理解不同断层的影响。此外，由于破坏性，不可能在变压器绕组中应用真实的机械变形来获得数据。为了解决这些问题，在本贡献中，使用三维有限积分分析模拟三相变压器的物理几何形状，以模拟真实的变压器运行。该模型的新颖之处在于无需估计和求解集总参数电路模型，直接从绕组的三维模型中获得FRA走线。首先，用一个简单的实验装置对该方法进行了验证。然后，对不同的机械和电气故障进行了仿真，客观地讨论了它们对FRA的影响。本文的一个重要贡献是引入了基于差分标准偏差（SDD）的绕组评估因子来检测和分类不同的电气和机械故障。结果表明，该模型具有较好的故障仿真能力。利用SDD可以对不同的故障表现出不同的偏差模式，为故障分类提供了可能。从而为建立可靠、自动化的变压器FRA结果评估标准算法提供了一条途径。
The measurement procedures for frequency response analysis (FRA) of power transformers are well documented in IEC and IEEE standards. However, the interpretation of FRA results is still far from reaching an accepted methodology and is limited to the analysis of the experts. The dilemma is that there are limited case studies available to understand the effect of different faults. Additionally, due to the destructive nature, it is not possible to apply the real mechanical deformations in the transformer windings to obtain the data. To solve these issues, in this contribution, the physical geometry of a three-phase transformer is simulated using 3D finite integration analysis to emulate the real transformer operation. The novelty of this model is that FRA traces are directly obtained from the 3D model of windings without estimating and solving lumped parameter circuit models. At first, the method is validated with a simple experimental setup. Afterwards, different mechanical and electrical faults are simulated, and their effects on FRA are discussed objectively. A key contribution of this paper is the winding assessment factor it introduces based on the standard deviation of difference (SDD) to detect and classify different electrical and mechanical faults. The results reveal that the proposed model provides the ability of precise and accurate fault simulation. By using SDD, different deviation patterns can be characterized for different faults, which makes fault classification possible. Thus, it provides a way forward towards the establishment of the standard algorithm for a reliable and automatic assessment of transformer FRA results.