变压器油纸绝缘热老化特性及特征量研究

对25#变压器矿物油、以BIOTEMP为代表的植物绝缘油、普通牛皮纸和热稳定绝缘纸材料构成的油纸绝缘试品进行了加速热老化实验,对老化过程中绝缘纸的聚合度变化规律及老化特性进行了对比分析,并对油中水分、糠醛含量这两个重要的老化特征参量的变化规律及其与聚合度的相关性关系进行了研究。研究的主要目的是探索新型绝缘材料的老化特性,为传统的老化特征参量应用于新型油纸复合绝缘材料构成的变压器老化诊断提供依据,并为拓展变压器寿命预测理论奠定基础。

Investigation on Properties and Characteristics of Oil-Paper Insulation in Transformer During Thermal Degradation Process

In this paper, accelerated thermal aging test for four types of oil-paper samples are performed at three temperatures of 90℃, 110℃and 130℃. The samples are composed of conventional 25~# mineral oil, BIOTEMP oil (which represents a kind of vegetable oil), ordinary Kraft paper and thermally-upgraded paper. The research on changing laws of degree polymerization (DP) of paper and aging properties of oil-paper are performed, and two characteristic parameters, furfural concentration and water content in oil, and also their relationships with DP are analyzed in this paper. The main purpose of this research is to investigate the aging properties of new material insulations and supply references for applying the current aging characteristics and diagnostic techniques to the new composite insulation and lay the basis for developing the lifetime prediction theory of power transformers.