Large Transformer Leakage Magnetic Field, Electric Field And Stress Field Of Finite Element Analysis

Large-scale electric transformers are important part of the power system. With the development of power system, the capacity and voltage grade of transformer becomes high. Then the insulation, leakage magnetic field and configuration intensity of oil box become the concern of design of transformers.In this paper, the electric field, leakage magnetic field and stress field of oil box of transformers are studied using finite element analysis software ANSYS. Based on the analysis results, improved measures are provided.In the analysis of electric field, 2D finite element method is used. Because the weakness of insulation is usually at the area of high voltage, the solution area is the top of coil. The analysis results show that the end of the high voltage coil is the dangerous area.In this paper, the effect and type of leakage magnetic field in transformers are discussed. The leakage magnetic field is intensive when power is bigger, so the losses in tank are high. If no measurements have been taken, the tank wall may have local hot spot that can deteriorate the transformer performance. It is necessary to calculate accurately the loss in the tank. 2-D and 3-D leakage magnetic field model of transformer are built using FEM. Results shows 3-D model is more accurate. and provide help for taking better shielding measures. The detailed analysis is given, Some new results which have both theoretical and practical significance are drown.In the analysis of press field of oil box, 3D finite element method is used. The model of the whole oil box is the solution area. The press field and the distortion of oil box is calculated. Based on the calculation result, optimization design measures are got.