Research on the characteristics of partial discharge gas generation in typical defects of oil immersed current transformers.

During the operation of oil-immersed current transformers, they gradually deteriorate due to various factors. In order to study the relationship between partial discharge and gas generation characteristics under different typical defects, this paper measures the unit-time discharge energy, unit-time apparent discharge quantity, pulse repetition rate, and gas generation rate during the discharge development process of three typical defects: protrusion defect, surface defect, and gas gap defect. The study reveals that the generation of hydrocarbon gases and hydrogen in the oil mainly depends on discharges with an apparent discharge quantity above 300 pC.