Failure Analysis of Electronic Current Transformer Air Chamber Basin Insulator Cracking in a 330 kV Substation

Abstract

Abstract In operation, the combined electrical appliances in the substation leak, and the insulation basin breaks when the old insulation basin is replaced. By using the methods of macroscopic inspection, penetration detection, material analysis, and scanning electron microscopy, the failure analysis of the broken basin insulator of the combined electric apparatus is complete, and the process of crack generation and expansion is analyzed. The analysis results show that the reason for the fracture of the basin-type insulator is uneven force during fastening or disassembling, subjected to shear and bending stress. The crack source starts at the stress concentration part, that is, the root of the groove of the inner ring seal ring, and continues to expand, resulting in the final fracture of the basin-type insulator. The next step is to strengthen the daily control of the transportation process and installation process of the basin insulator.