Study on explosion stress distribution of oil-immersed transformer based on actual gas model

In order to reveal the transmission process of transformer explosion stress in transformer oil and the influencing factors of transformer tank deformation, this paper adopts numerical calculation method, considers the influence of actual gas on simulation results, and introduces van der Waals equation to study the stress distribution law of transformer tank from two aspects: gas type in transformer oil and arc discharge position. Taking a general 110kV transformer as an example, the results show that the gas type is an important factor affecting the stress of the tank, and the actual gas model should be used for explosion analysis. When the arc discharge is at the lower end of the winding, the stress of the tank is larger. In general, when the explosion occurs, the stress value of the bottom and end of the transformer box is large.

Key words: oil immersed transformer; Stress propagation mechanism; Arc discharge; Stress distribution; Actual gas; Van der Waals equation; Gas type