In order to analyze the influences of the temperature and the inhomogeneity of magnetic field loss on the physical parameters of the material

a multi-physical field calculation method based on the non-uniform heat source is presented for more accurately obtaining the temperature distribution in the power transformer.This method adopts the advantages of finite volume and finite element method.The fluid field distribution is calculated using the upwind finite volume method so as to study the temperature field distribution of the transformer.Non-physical oscillations are effectively avoided by introducing an upwind difference in the solution.Through the data mapping method

the magnetic field loss distribution is mapped into the calculation grid of the temperature field

and then the non-uniform heat source of the temperature field is obtained.The proposed method is applied to calculate the temperature distribution and fluid field

and the results of the proposed method are compared with those of software Comsol for two-dimensional simplified model of converter transformer.The difference of the velocity peak obtained in the two methods is less than 0.03 m/s

and the maximum temperature difference does not exceed 3 K

which proves the accuracy and validity of the proposed method.At the same time

the difference of the temperature field distribution is compared and analyzed under uniform heat source and non-uniform heat source.The results show that the calculated results obtained by non-uniform heat source are more accurate than the uniform heat source compared with theoretical analysis

which can be provided as references for the life expectancy and the hot spot prediction of the transformer.