Simulation of Bubble Deformation and Motion Characteristics Under Different Electric Field in Transformer Oil

In power transformer, the electric field intensity will affect the shape of bubbles in transformer oil and change the motion characteristics of bubbles. However, there are few studies on bubble motion characteristics in oil under different electric field intensities. Therefore, according to the three-phase five-column transformer model, the internal electric field of the transformer is reasonably simplified, and the multi-physics simulation model of electric field and phase field coupling is established. The deformation characteristics of bubbles under different electric field intensities and the motion characteristics of the three-bubble model are studied. The simulation results show that under the action of electric field, there is electric field force on the gas-liquid interface, and the bubbles will stretch along the direction of electric field. The deformation of bubbles increases with the increase of electric field strength and bubble radius. In the three-bubble model, the electric field intensity is positively correlated with the coalescence velocity of bubbles. Without the application of electric field, the bubble after coalescence is hat-shaped. With the increase of electric field intensity, the bottom of the bubble is gradually smooth, and the inward depression is weakened. The simulation results are consistent with the related research results. The research results of this paper reveal the shape characteristics and motion characteristics of bubbles in transformer oil under different electric field intensities, and provide some reference for the design of transformer oil channel and electric field distribution.