热老化对变压器绝缘纸微观结构影响的实验研究

Experimental Research on Thermal Aging Effects on Microstructure of Transformer Paper

为了研究热老化应力对变压器绝缘纸微观结构的影响,以更准确地分析油纸绝缘机械强度和绝缘性能,文中对油浸纸试品进行加速热老化实验,获取不同老化程度的变压器绝缘纸试样。测量了绝缘纸试样的聚合度,采用扫描电镜观察绝缘纸试样的表面微观形貌,通过傅里叶变换红外光谱(FTIR)分析纤维素分子结构变化。分析结果表明,热老化对变压器绝缘纸微观纤维结构破坏显著,纤维细化,断裂增多,纤维分子结构及相关官能团数量变化明显。

To investigate thermal aging stress effects on microstructure of transformer paper for more accurate analysis of mechanical strength and insulation performance of oil-paper insulation,the accelerated thermal aging experiment is performed on oil-paper samples in this work and some samples of different aged states are obtained. The surface micro-topography of paper samples is observed by Scanning Electron Microscope（SEM）and the changes of molecular structure are analyzed by Fourier Transform Infrared Spectroscopy（FTIR）.Experimental results show that thermal aging stress brings significant changes to microstructure of paper fiber.The cellulose fiber becomes thinner and shorter. In addition, the molecular structure of cellulose fiber and the quantity of some function groups change obviously.