The paper presents a method for assessing the frequency response results of transformers. The frequency response analysis (FRA) method is widely used in the industrial testing of the mechanical condition of transformers, however, there are still some problems with interpreting the test results. The measurements are usually taken only in an end-to-end open measurement configuration, according to the IEC standard. The literature indicates many numerical indices that are used for the assessment of FRA curves. It is not possible to use all of them, especially as they may give different results. The objective of the presented research was to analyze the behavior of 14 of the most popular indices in the medium-frequency range under the influence of deformations. The experiments allowed them to be divided into four groups, based on similar behavior under data recorded in conditions of deformations introduced into windings. All research is performed for two measurement configurations: end-to-end open and capacitive inter-winding. The division into groups is also tested with data recorded on transformers from industry. The proposed grouped indices method needs only four indices for FRA data assessment, while their behavior covers all 14 analyzed formulas.

中文翻译：

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在端到端和电容式绕组间测量配置中使用分组指数方法进行变压器频率响应分析

本文提出了一种评估变压器频率响应结果的方法。频率响应分析（FRA）方法广泛用于变压器机械状态的工业测试，但是在解释测试结果方面仍然存在一些问题。根据 IEC 标准，测量通常仅在端到端开放式测量配置中进行。文献指出了许多用于评估 FRA 曲线的数值指标。不可能全部使用它们，尤其是因为它们可能会产生不同的结果。本研究的目的是分析 14 个最受欢迎的指标在变形影响下的中频范围内的行为。实验让他们分成四组，基于在引入绕组的变形条件下记录的数据下的类似行为。所有研究均针对两种测量配置进行：端到端开放式和电容式内绕组。分组也用工业变压器记录的数据进行测试。所提出的分组指数方法只需要四个指数进行 FRA 数据评估，而它们的行为涵盖了所有 14 个分析公式。