In view of excessive temperature rise of distribution transformer due to seasonal overload of power grid

it is proposed in this paper to install external cooling modules on the heat sink of oil-immersed distribution transformer to strengthen the heat dissipation ability of the transformer and reduce the hot spot temperature rise. For verifying the feasibility of this method

a set of type S13-M-200/10 distribution transformer is taken as the research object to set up a three-dimensional model. The external cooling module is set up on the heat sink of the transformer model. Four different calculation models are formed by changing the installation position and number of cooling modules. The finite volume method is used to calculate the hot spot temperature rise of each model under different load conditions. Some of the simulation results are verified by short circuit temperature rise test

and the error between simulation and calculation is less than 3 K. The test and simualtion results show that reasonable arrangement of external cooling modules can reduce the hot spot temperature rise of the oil immersed distribution transformer by approximately 10 K

which provides a new idea for reducing the temperature rise of the distribution transformer.