Multi-Physics Modeling and Simulation of Oil-Immersed Power Transformers Based on 3D Finite Element Analysis and Finite Volume Method

Power transformers are the essential components in almost every electric power network. Uninterrupted operation of power transformers plays a critical role in guaranteeing the reliability and safety of the power grid. In this paper, aiming at predicting the reliability of large power transformers, multi-physics modeling and simulations are carried out based on three-dimensional (3D) finite element analysis (FEA) and finite volume method (FVM). Specifically, FEA electromagnetic modeling and simulation is performed in Ansys Maxwell to extract the transformer winding losses. Afterwards, thermal model is established in Ansys Fluent to obtain the temperature distribution, and more importantly to identify the transformer winding hot-spot temperature (HST). Accordingly, aging acceleration factor is determined by the winding HST. A sensitivity analysis is also conducted to determine the effects of oil properties on the temperature distribution and HST.