电力能源发展与国家经济发展关系密切, 因此电网稳定、 安全地运行是人民稳定生活的保障。 而与稳定可靠的电网的运行有关的是变压器的绝缘水平, 因此始终注意电气设备的状况和运行非常重要。 而仅由纸绝缘产生的糠醛是目前用于评估电力变压器老化状况最常用的指标之一, 所以准确测量变压器油中糠醛含量具有重大意义。 拉曼光谱法可以实现对待测物的快速、 无损检测, 但受限于拉曼散射信号弱, 对油中老化特征物这种微量物质检测难度大。 表面增强拉曼光谱可以解决痕量物质检测的灵敏性问题, 使溶解在变压器油中的老化特征物得到快速、 无损地检测。 故将SERS应用到变压器油中糠醛的检测对于变压器运行状况的评估具有重要的意义。 围绕着变压器油中糠醛作为痕量物质检测灵敏度低的问题, 基于置换反应在TEM铜网上制备了微纳米结构的SERS基底, 以检测变压器油中的糠醛, 为高效, 准确地检测变压器油的老化水平提供一种快速、 有效的新技术。 选择了特定的实验材料, 在控制特定的实验条件下基于置换反应制备出微纳结构SERS基底, 经过电镜扫描对其表面形貌进行表征; 在不同位置进行拉曼检测得到特征拉曼峰峰强的变异系数仅为3.55%, 表明该基底的“热点”分布均匀和检测可重复性高; 定性分析了一定浓度梯度的变压器油中糠醛和背景噪声的拉曼光谱。 选择了1 702 cm^-1的拉曼峰作为油中糠醛的特征拉曼峰。 定量分析中, 建立内标峰和1 702 cm^-1处峰强比与变压器油中糠醛浓度的线性函数, 得到良好的线性关系。 使用3δ准则计算变压器油中糠醛在微纳结构SERS基底上的检测下限约为0.51 mg·L^-1。 研究说明基于铜网置换反应的微纳结构SERS基底对于变压器油中糠醛具有更灵敏的检测。 这对于诊断电力变压器绝缘状况和维护电网稳定非常重要。

The development of electric energy is closely related to the development of the national economy, so the stable and safe operation of the power grid guarantees the people’s stable life. The stable and reliable operation of the power grid is related to the insulation level of the transformer, so it is very important to always pay attention to the condition and operation of electrical equipment. The furfural produced only by paper insulation is currently one of the most commonly used indicators for evaluating the aging status of power transformers, so it is of great significance to accurately measure the furfural content in transformer oil. Raman spectroscopy based on the Raman effect can achieve rapid and non-destructive detection of the object to be tested, but limited by the weak Raman scattering signal, it is not easy to detect trace substances such as aging characteristics in oil. Surface-enhanced Raman spectroscopy technology can solve the sensitivity problem of trace substance detection and enable fast and non-destructive detection of aging features dissolved in transformer oil. Therefore, the application of SERS to detect furfural in transformer oil is of great significance for evaluating transformer operating conditions. In this article, around the problem of low detection sensitivity of furfural in transformer oil as a trace substance, a micro-nano structure SERS substrate was prepared on the TEM copper mesh based on the displacement reaction to detect furfural in transformer oil. It provides a fast and effective new method for efficiently and accurately detecting the aging level of transformer oil. In this paper, specific experimental materials are selected, the micro-nano structure SERS substrate is prepared based on the displacement reaction under controlled specific experimental conditions, and its surface morphology is characterized by scanning electron microscopy. Raman characteristics are obtained by Raman detection at different detection positions The relative standard deviation of peak-to-peak intensity is only 3.55%, indicating that the substrate has a uniform distribution of “hot spots” and higher detection repeatability; qualitative analysis of the Raman spectra of furfural in transformer oil with a certain concentration gradient and the Raman of the background noise spectrum. Combined with the selection rule of Raman characteristic peak, the Raman peak of 1 702 cm^-1 was selected as the Raman characteristic peak of furfural in oil. In the quantitative analysis, a linear function of the ratio of the standard internal peak to the peak at 1 702 cm^-1 and the furfural concentration in the transformer oil was established, and it was concluded that it has a good linear relationship. The 3δ principle is used to calculate the minimum detection concentration of furfural in transformer oil on the micro-nano structure SERS substrate, which is about 0.51 mg·L^-1. In this paper, the micro-nano structure SERS substrate based on copper mesh displacement reaction has a more sensitive detection of furfural in transformer oil. This is very important for diagnosing the insulation status of power transformers and maintaining the stability of the power grid.