Study on Change Law of Pressure and Hydrogen Gas Under Partial Discharge Defects in Transformer Bushing

For a long time, due to the lack of effective online monitoring technology for insulation status of transformer bushing equipment, some early latent local discharge insulation defects could not be detected early, ultimately leading to serious accidents. Recently, relevant research topics have gradually become the focus of researchers’ attention, but most of them have overlooked pressure as a direct influencing factor leading to explosions. Based on this, this paper builds a test platform for detecting pressure and hydrogen parameters of local discharge defects in transformer bushings, simulating common corona discharge defects in transformer bushings, and analyzing the correlation between pressure and hydrogen characteristic quantities and the severity of discharge. The study found that the hydrogen content of corona discharge defects increased at both 500 pC and 1500 pC discharge levels, while the pressure changes increased first and then decreased at 500 pC discharge level, and continued to increase at 1500 pC discharge level. Under short-time discharge conditions, the increase in pressure and hydrogen content almost linearly increases with time. The research results have certain engineering significance for the assessment of the operating state of transformer bushing equipment.