Modeling and Simulation Analysis of Transformer Hot Spot Temperature Based on Multi Physical Field Coupling Calculation and Temperature Rise Characteristics

The research on the temperature rise characteristics of transformer, especially the hot spot temperature measurement, is helpful to master the operation state of transformer, so as to avoid the occurrence of thermal fault and guide the dynamic capacity increase of transformer. Aiming at the improvement of the existing hot spot temperature calculation method, a temperature rise model of oil immersed transformer based on multi physical field coupling is proposed in this paper. Taking 500kV oil immersed transformer as an example, the thermal characteristics of transformer are analyzed by using the principle of energy conservation. Then, the mathematical and physical models of temperature field and flow field of transformer are established and the temperature rise characteristics, physical parameters and material characteristics of transformer are analyzed. The fluid-solid-thermal coupling temperature field calculation method is used for simulation calculation. Through simulation calculation and analysis, a deeper understanding of the specific distribution position and value of hot spot temperature is achieved. The accuracy of this method is 4% higher than that calculated by empirical formula, a new calculation idea for the calculation of transformer hot spot temperature is proposed.