Research on Simulation and Verification Experiment Method for Pressure Characteristics of Converter Transformer Tank under Internal Arc Fault

Internal electrical fault of converter transformer may generally cause high-energy arc. Internal arc fault will lead to rapidly increasing dynamic oil pressure and tank rupture. The leakage of oil with leakage high temperature may cause fire. Whether the mechanical strength of the tank for converter transformer can withstand this dynamic oil pressure is the decisive factor to determine whether a fire may occurs. In this paper, the mechanical characteristics, such as mechanical stress and deformation of the tank under internal arc fault are simulated and analyzed by FEM method, and some technical measures, such as flexible oil tank, to reduce the probability of tank rupture are proposed. Meanwhile, this paper puts forward a verification test method of mechanical strength of the tank for converter transformer based on arc test in the transformer oil.