The overpressure caused by arc fault in the oil tank can lead to a transformer explosion. Since the AC turret of transformers serves to connect the transformer windings with the AC busbar

the arc current can be extremely high if an earth fault arc occurs leading to potentially hazardous pressure. It is necessary to investigate the relationship between arc faults and pressure to reduce the risk of explosions. In this paper

a full-scale arc fault simulation test platform in the AC turret of transformers has been established

and arc fault tests were carried out at different arc currents and arc lengths. A simulation model of gas production and pressure has been established to investigate the mechanism of overpressure caused by arc faults. The result shows that an arc with a current of 40 kA can produce a pressure wave with a peak of 1.58 MPa. The pressure distribution

gas volume and temperature were obtained during the arc discharge through the simulation model. The arc length has a greater influence on gas production than the arc current leading to higher pressure. The study provides both experimental and theoretical bases for the explosion-proof design of AC turret.