油纸绝缘老化特征产物生成速率研究

Study on Generation Rate of Characteristic Products of Oil-paper Insulation Aging

变压器绝缘老化是影响电网稳定运行的重要因素之一。通过实验室加速老化试验并结合现场实际,对油纸绝缘的老化特性和机理进行研究,从而为变压器绝缘状态评估和寿命预测提供依据和参考。该文针对处于老化中后期不同初始老化程度的油纸绝缘,在80和130℃下对老化特性进行研究,得到各老化程度特征产物随老化时间的变化关系,并对老化特征产物的生成速率进行分析。结果表明:在该文的试验条件下,处于老化中后期的油纸绝缘,在后期继续老化过程中特征产物的生成速率随油纸绝缘初始老化程度的增加并不呈现递增趋势,而是成近似指数递减关系,这与纤维素绝缘纸降解过程中断键(葡萄糖单体间糖苷键)速率的变化一致。

Transformer insulation aging is one of the key factors that influence stable operation of power network. It is significant to study properties and mechanisms of oil-paper insulation through accelerated aging in lab and experiences in field. This can provide references for insulation assessment and lifetime prediction of transformers. This paper studied aging properties of oil-paper samples under temperatures of 80℃ and 130℃. These samples are all in their mid-end life and have different initial aging degrees. Developments of characteristic products with time were obtained and their generation rates were also analyzed. Results show that, under the conditions depicted in this paper, generation rates of characteristic products don＇t speed up with increase of samples＇ initial aging degrees, but are consistent with the change of bond scission rate of cellulose. When samples are in mid-end life and aged further, the generation rate decreases almost exponentially.