Analysis and Treatment of Abnormal Defects in Transformer Oil Chromatography

This article analyzes the cause of an abnormal defect in the oil chromatogram of a transformer, and puts forward control measures and suggestions. It is analyzed that the cause of the abnormal oil chromatogram of phase A and B of the main transformer is the poor contact o f the dynamic and static contacts of the unloaded tap changer, high temperature and overheatin g, and the development of contact ablation, resulting in abnormal oil chromatogram. The cause of the ablation of the dynamic and static contacts of the no-load tap-changer may be due to the installation and transportation (or electrodynamic shock or U-switch design and other factors), the contacts are not in close contact, the larger contact resistan ce causes the contacts to overheat, and high temperature conditions Sulfur corrosion occurs on the surface of the lower contact, and the corrosion product gradually deposits on the surface of the contact, which further aggravates the poor contact. Although passivation agent is added in t he later period, the protection effect of the passivation agent at high temperature is limited, and it can no longer protect the contact. Under the action of current, the dynamic and static contacts that cause poor contact are gradually ablated.