Thermal Analysis of Oil-Immersed Transformers Based on Flow-Temperature Field Coupling

The overall structure of an oil-immersed transformer is complex. Its heat dissipation process includes thermal convection, thermal conduction, and thermal radiation, so it is difficult to obtain its detailed temperature field distribution characteristics. The simulation model developed in this paper to establish the flow-temperature field coupling of a 20 kV oil-immersed transformer is obtained after analyzing transformer losses and heat transfer. In addition, the distribution of the temperature field of the oil-immersed transformer as well as the analysis of the law of the transformer temperature field distribution are obtained. The result indicates that the hot point temperature of the transformer is 63.73 ℃ while the hot point is distributed at about 1/3 from the upper end inside the low voltage winding.