Simulation calculation of fluid field- thermal field of oil-immersed transformer and optimization of winding structure parameters

The optimization method of winding structure parameters of oil-immersed transformer is proposed to reduce the hot spot temperature of transformer and the metal conductor consumption based on the coupling calculation method of electromagnetic-fluid-thermal. Firstly, a 3-D simulation model is established by using finite element software, and the distribution of the thermal field and the fluid field around the transformer as well as the fluid field and thermal field of the low-voltage winding are obtained. Considering the calculation efficiency and accuracy, a 2-D model of transformer low-voltage winding is established, and the thermal field and flow field distribution of the two models are compared and analyzed. The temperature error was less than 5.98?, which verified the accuracy of the equivalent model. On this basis, combined with Latin hypercube experiment design and thermal field simulation method, the response surface model of winding hot spot temperature and structural parameters is established. Taking the hot spot temperature of low voltage winding and the amount of metal conductor as optimization objectives, the optimal solution set of Pareto is obtained by using NSGS-? optimization algorithm, and two kinds of optimal design results are obtained on the Pareto front surface. The results show that the hot spot temperature is reduced by 4.16% and the metal conductor consumption is reduced by 13.79% in Scheme 1 and the hot spot temperature is reduced by 0.51% and the metal conductor consumption is reduced by 28.46% in Scheme 2. The research results have important guiding significance for the optimization of oil-immersed transformer.