Study on the effect of bubble motion characteristics on insulation performance of transformer oil based on COMSOL Multiphysics

Transformer realizes the role of voltage and current transformation and isolation in the power system, and is indispensable electrical equipment in the power system, while transformer oil, as one of the important insulation means of transformers, is very important to study its insulation performance. In this paper, for the phenomenon of partial discharge of bubbles in transformer oil, we use COMSOL simulation software to construct a double-bubble vertical oil channel model with three coupled temperature, flow, and electric fields and study the radius of bubbles in transformer oil and the effect of transformer oil flow rate on the bubble deformation, and then study the effect of bubbles on the insulation performance of transformer oil. Finally, we found that when the two bubbles are just in contact, the electric field strength at the bubble connection is the largest, which has the greatest effect on the insulation performance of transformer oil.