基于中红外光谱分析热老化对变压器油性能影响

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第48卷第6期当代化工 Vol.48，No.6 2019年6月 Contemporary Chemical Industry June，2019 DOI:10.13840/j.cnki.cn21-1457/tq.2019.06.011

丘晖饶，贺石中，车超萍

（广州机械科学研究院有限公司设备润滑与检测研究所，广东广州 510530）

摘要：以500 kV的在用变压器油作为研究对象，在实验室中用150 ℃加热老化试验，探讨了热老化对变压器油的氧化性能和电气性能的影响。运用中红外光谱对不同老化时间样品进行扫描得到红外光谱，同时测

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试了变压器油中T501、酸值、介电损耗常数、击穿电压和碳族组成。试验结果表明：变压器油在3 650 cm处酚类抗氧化剂的伸缩振动吸收峰强度随着老化时间明显降低，并以此特征吸收峰建立了T501红外光谱定量检测的标准曲线，相关系数为0.999 964；变压器油深度老化后在1 700 cm-1处出现C=O伸缩振动吸收峰，此时酸值明显增加，T501仅剩0.01%，变压器油的氧化安定性迅速下降。变压器油老化过程中，介电损耗常数随着老化时间的增大而增大，击穿电压随着老化时间增加而降低。通过对变压器油的中红外光谱分析，探讨了绝缘油老化过程和机理，发现热老化对变压器油的抗氧化性和绝缘性能有很大的影响。。关键词：红外光谱；热老化；变压器油；介质损耗常数；击穿电压；酸值；碳族组成中图分类号：TQ 64 文献标识码： A 文章编号： 1671-0460（2019）06-1154-04

Study on Influence of Thermal Aging on Properties of Insulating Oil based on the Mid-infrared Spectrum Analysis

QIU Hui-rao, HE Shi-zhong, CHE Chao-ping

（Guangzhou Mechanical Engineering Research Institute Co., Ltd., Guangdong Guangzhou 510530, China）

Abstract: The 500 kV transformer oil was used as the research objects, and thermal aging test at 150℃ was carried out in laboratory, the effect of thermal aging on oxidation properties and electrical properties of insulating oil was investigated. The infrared spectrums of samples with different aging time were obtained by FT-IR., Meanwhile, T501,acid number, dielectric loss constant, breakdown voltage and carbon group composition of transformer oil were tested. The results showed that: the intensity of stretching vibration absorption peak of insulating oil’s phenolic antioxidants at 3 650 cm-1 decreased significantly with aging time, based on the characteristic absorption peak, the standard curve of T501 infrared spectrum quantitative detection was established, and the correlation coefficient was 0.999 964. After aging deeply, C=O absorption peak appeared at 1 700 cm-1,at this point, the acid number increased significantly ,only 0.01% T501 remained in transformer oil ,the oxidation stability of oil decreased. In the aging process, the dielectric loss constant increased with the aging time, and the breakdown voltage decreased with the aging time. The aging process and mechanism of insulating oil were analyzed by FT-IR. It's found that thermal aging had a great influence on the oxidation and electrical performances of the insulating oil..

Key words: FT-IR spectrometry; Thermal aging; Insulating oil; Dielectric dissipation factor; Breakdown voltage; Acid number; Carbon compositions

变压器油是源于石油的一种分馏产物，它的主要成分是具有特定分子量的烷烃、环烷烃的饱和烃类和芳香族不饱和烃类等的化合物。变压器油的性能是保证设备安全运行的重要条件，它在变压器运

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行中起到循环、冷却和绝缘等作用。

击穿电压、介质损耗常数等是表征其绝缘特性的主要性能指标。击穿电压是指将变压器油置于含有电极的油杯中，按一定速率施加连续升压，当油的电阻突然下降，电流瞬间突增，并由火花或电弧通过变压器油，变压器油被“击穿”，此时的临界电压成为击穿电压。介质损耗常数对油中存在的可溶

性记性杂质、老化产物以及带电胶体的反应敏感。

变压器在长期运行过程中，油纸绝缘持续承受电、热等多种应力作用，变压器油（矿物绝缘油）主要组分为饱和烃类，烃类化合物容易被空气中的氧不断氧化，会出现氧化、老化等现象，生成醛、酮、酸、酯和油泥等劣化产物，其绝缘性能和抗氧

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化性能逐渐下降，严重影响变压器油的使用寿命。目前，主要通过加热老化的方式分析变压器油老化

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的性能。吴海燕用旋转氧弹法对变压器油加速老化，进行了加氢变压器油和环烷烃变压器油抗氧化

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