Condition monitoring of the insulating system within power transformers has a massive importance according to the electrical utilities. Dissolved gas analysis (DGA) is frequently used for this purpose. However, DGA lacks the necessary level of accuracy to identify all equipment faults, particularly in their initial stages of degradation. Also, it does not have the capability for real-time monitoring and relies on manual sampling and laboratory testing, causing potential delays in fault identification. Additionally, the interpretation of DGA data necessitates specialised expertise, which may pose difficulties for smaller entities that have limited access to resources. Therefore, the contribution of this research is to use infrared spectroscopy measurements as a new effective technique substituting the DGA method for fault diagnosis in insulating oil. The inception faults that were considered in this study were the electrical fault (discharges of high energy) and the thermal fault (300°C < Temperature <700°C). Regarding that, two test cells were crafted especially for serving the simulation processes inside the laboratory for both types of inception faults. Subsequently, six samples of pure paraffinic mineral oil were taken to be degraded in the laboratory. Following that, all of them besides another sample that were not subjected to any kind of faults were taken to be examined by Fourier transform infrared (FTIR) spectroscopy to obtain an overview of the oil's behaviour in each fault case. After that, the FTIR analysis was initially verified utilising the DGA method. Then, for further affirmation, the dielectric dissipation factor (DDF) for all samples was measured. In the final analysis, the verification tests provide experimental evidence about the outperformance of this new optical technique in detecting the transformer's inception faults in addition to proving its potential for being a superior alternative to the well-known traditional diagnostic techniques.

中文翻译：

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基于红外光谱测量的变压器绝缘油故障诊断新技术

根据电力公司的说法，电力变压器内绝缘系统的状态监测非常重要。溶解气体分析 (DGA) 经常用于此目的。然而，DGA 缺乏必要的准确度来识别所有设备故障，特别是在故障的初始阶段。此外，它不具备实时监控能力，依赖于人工采样和实验室测试，导致故障识别存在潜在的延迟。此外，DGA 数据的解释需要专业知识，这可能会给资源有限的小型实体带来困难。因此，本研究的贡献在于利用红外光谱测量作为替代DGA方法进行绝缘油故障诊断的一种有效的新技术。本研究中考虑的初始故障是电气故障（高能放电）和热故障（300°C < 温度 <700°C）。为此，专门设计了两个测试单元，用于在实验室内为两种类型的初始故障提供模拟过程。随后，取六份纯石蜡矿物油样品在实验室进行降解。随后，除了另一个没有出现任何故障的样品之外，所有这些样品都被进行了傅里叶变换红外（FTIR）光谱检查，以获得每个故障情况下油品行为的概述。之后，利用DGA方法对FTIR分析进行了初步验证。然后，为了进一步确认，测量了所有样品的介电损耗因数（DDF）。归根结底，验证测试提供了实验证据，证明这种新型光学技术在检测变压器初始故障方面的卓越性能，此外还证明了其作为众所周知的传统诊断技术的卓越替代方案的潜力。