变压器油热老化过程中性能变化及红外光谱分析

Performance Change and Infrared Spectrum Analysis of Transformer Oil During Thermal Aging

通过对45#变压器油分别在90℃、110℃、130℃条件下进行为期49天的分周期热老化试验,密切关注了老化过程中油的红外光谱、水分、酸值、界面张力、击穿电压、介质损耗因数、体积电阻率等性能指标的变化,并对各性能的失效情况进行了跟踪分析。结果表明:老化过程中,90℃和110℃条件下仅有抗氧剂消耗并无新物质生成,而130℃条件下老化过程中不仅有抗氧剂的消耗还有新的羰基化合物生成;在90℃和110℃条件下老化49天,油品均未达到失效标准;在130℃条件下老化时,油的理化性能失效普遍比电气性能早,理化性能中最早出现失效的是酸值,它在老化14天后就已达到失效标准,而红外谱图在老化14天时,1710 cm-1处也出现了明显的新的C=O吸收,吸光度高达11.237,说明红外响应敏感,可以作为油品老化程度评估的特征量。

Through 49 days of periodic thermal aging tests on 45#transformer oil at 90℃,110℃and 130℃,the infrared spectrum,water content,acid value,interfacial tension,breakdown voltage,dielectric loss factor and volume resistivity of the oil during the aging process were studied closely.The failure of each performance were tracked and analyzed.The results show that during the aging process,only antioxidants are consumed and no new substances are generated at 90℃and 110℃,while during the aging process at 130℃,not only antioxidants are consumed but also new carbonyl compounds are generated.Under the aging condition of 90℃and 110℃for 49 days,the oil does not reach the failure standard.While in the case of 130℃,the physical and chemical properties of the oil generally fail earlier than the electrical properties.The earliest failure comes the acid value,which occurs after 14 days of aging.As to the infrared spectrum,the new C=0 absorption was also found at 1710 cm-1,and the absorbance was up to 11.237,indicating that the infrared response was sensitive and could be used as a characteristic factor to evaluate the degree of aging of oil products.