A 2D model of 500 k V ultra-high voltage oil-immersed transformer is built. The two-dimensional steady laminar flow in the model is simulated using the Laminar model based on the software Ansys Fluent

and the temperature distributions and the position of hot spot within the transformer are obtained.The position effect of the angle rings at winding end on the thermal property of oil is analyzed. Simulation results are consistent with the experimental ones

which infers that the numerical simulation method on the basis of ANSYS Fluent is applicable to temperature field analysis of ultra-high voltage transformers. This study may provide a tool for design

research and development

and test of ultra-high voltage transformers.