Heat dissipation performance analysis and cooling module optimization of oil-immersed transformer based on multi-physical field simulation

The long-term operation of oil-immersed transformers causes rapid internal temperature rise, which may lead to accidents such as transformer burning, which has a certain impact on the safe and reliable operation of the power grid. This paper uses finite element simulation to establish a 3-D circuit-magnetic field model based on transformer parameters, accurately calculating core and winding losses. The calculated loss is loaded into the simulation model of the flow temperature field, and the distribution characteristics of the temperature field and flow field of the transformer core and winding are obtained accurately by analyzing the heat transfer mode of the transformer. Through central composite design and range analysis, optimal winding geometry parameters minimizing hot spot temperature are determined. In order to further reduce the temperature rise of the transformer, the principle of enhanced heat dissipation is used, and the cooling module is attached to the radiator of the transformer model, with its shape, position, installation method, and quantity optimized via heat-flow coupling calculations to obtain the optimal scheme to minimize the hot spot temperature of the transformer. The results show that the hot spot temperature of the oil-immersed transformer can be reduced from 78.1? to 60.7?, and the hot spot temperature can be reduced by 22.3%. The aforementioned research provides a new idea and reference for oil immersed transformer to reduce temperature rise and improve heat dissipation performance.