The Influence of Electrode Structure on the Discharge Characteristics of Power–Frequency Arc in Insulating Oil

Abstract

Internal short-circuit arc fault is one of the most severe transformer faults. This fault might cause transformer explosion accidents, resulting in poor social impact and substantial economic losses. There is an urgent need to study explosion-proof technology for transformers. An in-depth study of the discharge characteristics and influencing factors of the power-frequency arc in oil is the basis for transformer explosion-proof research. This article conducts ten arc experiments on each of the four different electrode structures (rod-rod, rod-plate, rod-plate–paper, and plate-plate–paper). The effect of electrode structure on discharge characteristics is analyzed in terms of arc energy, pressure wave, bubble shape, gas production, and electrode ablation. The results show that the arc discharge energy affects the gas production process. At the same time, a high-temperature and high-pressure bubble creates pressure waves, and the bubble and pressure will, in turn, affect arc discharge. Arc discharging, gas generating, bubble pulsing, and tank deforming are coupled. Electrode structure significantly affects the shape of the bubble and arc, changing the gas production, arc energy, pressure wave, and other characteristics. This article analyzes the coupling relations during arc discharging by changing electrode structures. This work supports further simulating the power-frequency arc discharge in oil.