Dispersion Staining Method for Extracting Image Characteristics of Suspended Fibers in Transformer Oil

In order to extract the new aging characteristics of suspended fibers in insulating oil and solve the defects in the application of current aging characteristics of transformer paper insulation, the accelerated thermal aging experiments of transformer oil-paper insulation and the experiment of image characteristics acquisition based on dispersive staining method were carried out at 90°C, 110°C and 130°C, respectively. The suspended fibers in insulating oil were obtained, and the dispersion staining images of suspended fibers under different aging degrees were observed. Through image processing technology, the extraction of aging characteristics of dispersion staining images were acquired with the optimal expansion radius and optimal corrosion radius. The results showed that: As aging progressed, the dispersion staining color of the suspended fibers in insulating oil gradually changed from the initial blue to red and orange, the proportion of blue of the three primary colors gradually decreased, while the proportion of red gradually increased, and the color inhomogeneity increased at first and then decreased. The extracted three primary color proportion and color inhomogeneity can be used as reliable predictors of the aging degree of oil-paper insulation, showing its application potential in the aging life evaluation and condition diagnosis of transformers.