The three-phase integrated transformer can reduce the volume of magnetic components and improve the power density of the three-phase isolation topology system. The heat dissipation design of high-frequency transformer is a key technology that affects its efficiency, insulation life, and power density. In this paper, the loss of the three-phase integrated transformer is calculated based on the Dowell and iGSE model. An optimized heat dissipation structure is proposed based on temperature rise distribution. A thermal resistance model is established and verified by thermal simulation using Flotherm XT. The results show that the transformer temperature rise of the optimized heat dissipation structure is reduced by 10.7 ℃ compared with the traditional heat dissipation structure. The error between the established thermal resistance model and the simulation is within 5%.

Heat dissipation structure, loss model, thermal resistance model, three-phase integrated transformer.