Typical Defect Judgment Method Based on Gas Generation Characteristics of Oil-Impregnated Paper Bushing

Oil-immersed paper bushing is one of the common outlet components of power transformers, and it is an indispensable electrical equipment of the power system. Oil-impregnated paper bushing defects are of various types, and there is a lack of experimental research on the typical judgment method for different defects and the design of solid models for different defect types. Based on the gas production characteristics to determine the typical defects of oil-paper insulated bushing has a better accuracy. This paper firstly establishes a typical defect model of oil-impregnated paper bushing, including: contact overheating of current-carrying connectors, X-wax inside the capacitor core, partial discharge of the capacitor core and discharge along the surface of the porcelain insulator. Secondly, the equivalent test is carried out by simulating the actual operating conditions, and the types of dissolved gases in the oil and the gas production rate laws are obtained under different typical defects test models. Based on the test results, the judgment method of typical defects are proposed. The research in this paper has reference value for the diagnosis and analysis of typical defects of oil-impregnated paper bushing.