电力变压器用绝缘纸热老化的微观结构及形貌研究

Research on the Microstructure and Morphology of Power Transformer Insulation Paper After Thermal Aging

对绝缘纸在热老化过程中微观形貌、纸纤维的结构以及其超微结构等的变化发展进行研究。通过对比绝缘纸样品的原子力显微镜图片,发现初始绝缘纸纤维素的原子排列致密而有序,但经过加速热老化后葡萄糖单体的六边形结构受到破坏。此外,通过扫描电镜照片可以发现纤维素的细胞壁在老化过程中逐渐破裂,同时纤维素的长度及粗度均有减小。通过X光衍射分析显示绝缘纸样品的结晶度及晶粒尺寸在老化过程中逐渐减小,但仍保持原有的纤维素晶型和两相共存的微细结构。试验证明,绝缘纸老化的微观结构研究对进一步了解绝缘纸纤维老化的发展过程及其老化机理有很好的帮助。

We studied the microcosmic appearance of insulation paper, paper-fiber structure, and ultrastructure. Through the comparison of some specimens＇ AFM figures, we discovered that the molecular arrangement of the initial cellulose paper is close and ordered, some of the hexagonal mesh structures of the D-glucopyranose units were broken down after a few weeks accelerated thermal aging. What＇s more, according to the SEM photo, we find that the cell wall of cellulose paper disrupted, and the length and width of fibres diminished. In addition, X-ray diffraction analysis indicates that the relative crystallinity and the grain size of specimen have a trend of descending, but the crystal type and fine structure of cellulose insulation paper haven＇t change. The experiment indicates that research on the microstructure of insulation paper can have very big help on researching the aging developing process and aging mechanism of power transformer insulation paper.